The best player in baseball will hit the disabled list for the first time in his career. Los Angeles Angels outfielder Mike Trout tore his UCL ligament in his left thumb, and is will miss 6-8 weeks as he recovers from the injury.

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Angels general manager Billy Eppler confirmed the diagnosis, and said Trout would discuss a treatment plan with the club.

After some deliberation, Trout decided to have surgery to repair the injury. He’s expected to miss 6-8 weeks.

Trout suffered the injury while sliding into second base on a steal attempt during Sunday’s game against the Miami Marlins. In the fifth inning, Trout stole second with Cole Kalhoun at the plate. Once he arrived at the bag, he winced in pain and pulled up his left hand.

Trainers came out to take a look at Trout, but he stayed in the game at first. He was later removed from the contest and diagnosed with a thumb sprain. Initial X-rays came back negative. An MRI revealed the injury Monday.

It’s tough to understate an injury of this magnitude. By pretty much every measure, Trout is, and has been, the best player in baseball. Since 2012, he leads all of baseball with a 50.6 fWAR. Clayton Kershaw ranks second with a 37.6 fWAR over the same period.

Even if you despise WAR, it’s tough to pick apart Trout’s numbers. Over the last five seasons, Trout ranks fourth in home runs, first in runs scored, sixth in RBI, third in batting average, second in on-base percentage and first in slugging percentage. He’s also won two MVP awards, though there are legitimate arguments he should have won five.

While little was expected of the Angels this season, losing Trout for a number of weeks essentially sinks their playoff hopes. Though the team is under .500 at 26-27, they are only two games out of a wild card spot.

Considering all of Trout’s contributions, it’s going to be incredibly tough for them to remain in that position over the next few weeks. Trout was once again off to a fantastic start, hitting .337/.461/.742, with 16 home runs, over 206 plate appearances.

He is, not surprisingly, already leading baseball with a 3.6 fWAR. He’s also leading in home runs, walks, on-base percentage and slugging percentage. By wRC+, an advanced stat that measures offensive performance, Trout was off to his best start ever.

Despite that, there’s some hope for the Angels. The Los Angeles Dodgers were able to get by without Kershaw last year. The team somehow went 38-24 without their ace, catching the San Francisco Giants and surging to the top of the National League West. Winning without Trout is going to be difficult, but it’s not impossible.

It feels that way, though. Trout has been far and away the best player in baseball over the past five seasons, and was well on his way to another MVP-caliber season this year. No one player is going to replace Trout’s production. Heck, multiple players would likely struggle to bring the same value.

We’re about to see what happens when the most irreplaceable player in baseball goes down. It’s not going to be pretty.

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Chris Cwik is a writer for Big League Stew on Yahoo Sports. Have a tip? Email him at christophercwik@yahoo.com or follow him on Twitter! Follow @Chris_Cwik