With the group stage in the rear-view mirror, the men's basketball tournament at the 2012 Summer Olympics moves to the knockout stage on Wednesday, with eight teams vying for a slot in the tournament semifinals and a shot at leaving London with a medal. Let's take a look at the players and matchups that could determine four intriguing games on what ought to be a tremendous slate of quarterfinal games.

And hey — whether you're watching the main-event game between Team USA and Australia at home or can't catch the action live, follow along with us here at Fourth-Place Medal! We'll be live-chatting throughout the game, taking your questions and comments, starting at 5 p.m. ET.

Russia vs. Lithuania, 9 a.m. ET

Much will be made of the historical underpinnings of Wednesday's first matchup, and for good reason. After five decades of occupation by Soviet and Nazi forces, Lithuania declared independence from the U.S.S.R. in 1990; the Soviet Union fell in December 1991, giving way to a Commonwealth of Independent States (CIS) formed by former Soviet republics, including the Russian Federation. At the 1992 Summer Olympics in Barcelona, a Lithuanian national team led by legends Arvydas Sabonis and Sarunas Marciulionis squared off with a CIS team featuring FIBA great Alexander Volkov, with the winner of the politically fraught matchup taking home both bronze medals and a measure of athletic bragging rights for its newly formed nation.

On that day, Lithuania prevailed; on Wednesday, 20 years later, they'll be underdogs.

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Lithuania's become a knockout-round mainstay over the past two decades, making five straight Olympic semifinals and seeking a sixth consecutive run here. But Russia's become one of the fastest rising nations in international play in recent years; while Lithuania won their last competitive matchup, notching an 86-79 win in pool play at the 2008 Games in Beijing, Russia outpaced Lithuania at the 2011 EuroBasket tournament, earning bronze medals while Lithuania took fifth place, and looked like the stronger side at the 2012 FIBA World Olympic Qualifying Tournament, where both booked passage for London.

After squeaking through pool play with a 2-3 record thanks to a last-day win over an underwhelming Nigeria side, Lietuva faces a 4-1 Russian side that came out atop a tough Group B under firebrand coach David Blatt thanks to stellar play from inside-out duo Andrei Kirilenko and Alexey Shved, strong performances from glue-guy Victor Khryapa, a steady diet of low-post bruisers Sasha Kaun and Timofey Mozgov, and timely contributions from role-playing guards Vitaly Fridzon and Anton Ponkrashov. This is a deep, talented Russian team that has still yet to really fire on all cylinders, and that should concern Lithuania coach Kestutis Kemzura, whose seen his own team alternate soaring heights and crashing lows.

Behind savvy veteran Sarunas Jasikevicius running masterful pick-and-rolls to activate frontcourt scoring threats Linas Kleiza, Martynas Pocius and Darius Songaila, Lithuania looked like world-beaters for 35 minutes of its Saturday loss to the United States. But for lengthy stretches of group play, Kemzura's squad has struggled with turnovers, inconsistent shooting and intermittent defensive effort; granted, their pool-play losses came to medal contenders France and Argentina, but Lithuania's had more than enough unsteady moments on both ends of the court to balance out the smooth, ruthless efficiency they showed against the U.S. They're going to need every ounce of Kleiza's offensive punch, Jasikevicius' control of pace and bull-in-a-china-shop play from the likes of Songaila and Jonas Maciulis to battle with Russia's size and scoring.

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The difference may well be the play of Shved, the 23-year-old point guard who set NBA fans' hearts aflame with dazzling performances in wins over Great Britain and China, but who showed flashes of wildness and inconsistency against Brazil and Australia, and was a virtual non-factor against Spain, playing just seven ineffective minutes. If Shved's the live wire he was at the start of group play, Lithuania's backcourt doesn't have an answer for him; if the young triggerman's off his game, Lithuania could pull the upset, derailing Russia's bid for its best finish since the end of the Cold War.

France vs. Spain, 11:15 a.m. ET

Kind of a bum run of luck for France, huh? It bounces back from an Olympics-opening pasting at the hands of the United States to win four straight games, finishing second in Group A behind a run of strong play from gifted young swingman Nicolas Batum and occasional bouts of brilliance by point guard Tony Parker ... and when the knockout-stage bracket's solidified, it finds it's drawn a Spanish side that handed it a 13-point loss in the EuroBasket finals back in September.

And that was with a healthy Joakim Noah to man the middle and match strength with the three-headed low-block monster of Pau Gasol, Marc Gasol and Serge Ibaka. This time around, Noah's on the shelf, meaning the task of doing battle with Spain's size falls to the trio of Ronny Turiaf, Kevin Seraphin and Ali Traore. But you know what? That might not be too far-fetched.

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None of France's three big men profile as suitable matches for the Gasols and Ibaka, but each turned in solid performances in group play — Turiaf's seven-point, nine-rebound effort against the U.S. and his 10-rebound, two-block turn against a nasty Lithuanian frontline; Traore's surprising 12-and-five showing against the U.S. and good minutes with Turiaf resting against Nigeria; and three nice showings by the young Seraphin against Nigeria, Tunisia and especially Argentina, where he held his own against the likes of Luis Scola and Andres Nocioni to the tune of 10 points, seven rebounds and three blocks in just 14 minutes. Yes, the Spanish troika's posted gaudy numbers — they combined to average better than 40 points per game in pool play, along with nearly 15 rebounds, six assists and four blocks — but they haven't been uniformly dominant from start to finish (witness the relative ineffectiveness of Marc and Serge against Russia and Great Britain).

France's bigs don't have to win their matchups; they just have to prevent Spain from getting that devious high-low game going and using pinpoint passing to run Les Bleus off the floor. If they can do that and France can play to its strengths — namely, winning on the wings with Batum continuing to impact the game on both ends (he averaged 19.3 points, 6.8 rebounds, 1.8 blocks, 1.5 assists and 1.3 steals per game in France's four post-USA wins) and at the point, with a rounding-into-form Parker outdueling Jose Calderon — then France stands an excellent chance of overcoming a Spanish team that hasn't yet looked quite up to its No. 2 FIBA ranking in London. But if Parker and Batum aren't two of the three best players on the floor — if, say, the heretofore quiet Juan Carlos Navarro gets hot and starts roasting the French backcourt like he did at EuroBasket — then France's lack of scoring depth could prove fatal.

(One other subplot worth watching: Keep an eye out for any stretches where Spanish swingman Rudy Fernandez and France's Mickael Gelabale get matched up on the wing. After their recent altercation during a pre-London exhibition, such interactions could be spicy.)

Brazil vs. Argentina, 3 p.m. ET

Two South American rivals with talented, dirty-work-friendly frontcourts and smart, sharp guard play ... both of whom looked alternately world-class and very beatable in the group stage ... with the man who led Argentina to gold in Athens in 2004, head coach Ruben Magnano, now wearing the green and yellow on the sidelines ... and an 80-75 Argentina win in the finals of the 2011 FIBA Americas Championship still stuck in the Brazilians' craw. This just feels like it's going to be a slugfest, doesn't it?

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Argentina's got the more accomplished, tournament-experienced starting five, a group that elevates team chemistry to an art form and boasts one of the world's most potent one-two punches in Luis Scola and Manu Ginobili, the third- and fourth-leading scorers in group play. But Brazil's a younger, deeper team, with nine players averaging at least five points per game in the prelims, a big-man rotation (Nene, Anderson Varejao and Tiago Splitter) capable of locking horns with Scola and Andres Nocioni, and a hot-shooting off-guard of their own in Leandro Barbosa, fresh off roasting Spain in the fourth quarter of their final pool-play contest.

The matchup to watch here looks to be at the point. If the bout of "renal colic" (aka kidney stones) that has sidelined Argentine point guard Pablo Prigioni for two of the last three games renders him either unable to go — or limits him to short, quiet minutes, as it did against Nigeria — then young Facundo Campazzo will have to bear the burden of matching up with Brazil's Marcelinho Huertas, perhaps the best point guard outside the NBA. Campazzo showed flashes in group play, rolling up a 22-5 assist-to-turnover ratio, but handling the veteran Huertas should prove to be a stern test for the 21-year-old.

Brazil will look to Huertas to control the pace of the game, combining with Splitter in the two-man pick-and-roll game they worked so effectively throughout the first five games; Magnano might look also to sic reserve guard Larry Taylor, a dogged defender capable of hounding opponents the full 94-by-50, on either an infirm Prigioni or inexperienced Campazzo in hopes of creating some havoc in the backcourt and interrupting the flow of Argentina's often metronomic half-court attack. (It'd also be nice to see Brazil get Nene — more of a rim protector and rebounder in London than he is in the NBA — activated in the offense, as he averaged fewer than four field-goal attempts in 21 minutes per game through his four preliminary appearances.)

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As is so often the case in international play, long-range shooting could prove to be the deciding factor in this one. Argentina attempted the fourth-most 3-pointers per game (23.8) in group play, made more per game (nine) than any team but America, and connected at a higher clip (37.8 percent) than all but the U.S. (45.8 percent) and Wang Shipeng-led China (39.1 percent). Brazil, for its part, took nearly five fewer long balls per game than Argentina and missed more than two out of every three deep shots they took.

Expect Argentina to pack the paint, looking to take away Splitter's room to operate and daring the likes of Barbosa and Marquinhos Vieira Sousa to beat them. On the other side, if Ginobili and Carlos Delfino — a difference-maker in wins over Lithuania, Tunisia and Nigeria, a relative non-factor in losses to France and the United States — can get comfortable from distance early, the Brazilian defense could find itself scrambling to run Argentine shooters off the 3-point line, breaking down Magnano's scheme and opening all kinds of room for Scola to work inside, which would spell disaster for Brazil.

United States vs. Australia, 5:15 p.m. ET

To my eyes, this one breaks down pretty simply. Australia needs its best performance from everyone — the 39-point Patty Mills of the win over Great Britain, the 20-on-11-shots Joe Ingles and little-bit-of-everything Matthew Dellavedova of the win over Russia, the 17-and-7 David Andersen of the win over China, etc. It needs the combo of rugged captain Matthew Nielsen and Gregg Popovich disciple coach Brett Brown to inspire the nastiest defense the Boomers can muster.

It needs bigs Aleks Maric and Aron Baynes to bang America's frontcourt early and often. It needs Team USA to play the brand of defense that nearly netted Lithuania an upset and kept Argentina close through two quarters. It needs multiple U.S. shooters — Kevin Durant, Carmelo Anthony, LeBron James, Chris Paul, Kevin Love, take your pick — to continue settling for 3-pointers and go ice-cold from long range. It needs USA coach Mike Krzyzewski to forget what the numbers say and refuse to go big.

If all that goes Australia's way, the Boomers should be within 15 in the fourth. From there, who knows what can happen?

Kidding aside, Australia's a tough, physical, competitive, well-drilled team that likes to get up and down — if you haven't yet caught Spurs guard Mills in the open floor, a word of advice: don't blink — and finished group play winning its final three games. They're not going to be awed by the U.S., and they're going to make Team USA work to score. But unless they improve leaps and bounds on the 43.2 percent mark from the floor they managed in group play, all that defensive work will likely be for naught.

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