For many years in the NFL, trading during the season was an afterthought. We went many years without a significant deal before the deadline.

That has changed the past decade or so. Teams are more willing to ship off players at or near the deadline, usually when they understand their season is going nowhere and it's best to grab some future draft picks.

With the trade deadline coming up on Tuesday, here are the 12 biggest in-season trades in NFL history:

12. Trent Richardson to the Colts

How big this trade was will fade as time goes on. But in 2013, the Browns trading Richardson, a former No. 3 overall pick, to the Colts for a first-round pick was huge news. And it turned out horribly for the Colts, as Richardson averaged just 3.1 yards per carry over his two Colts seasons. He played his final regular-season game in 2014, about 15 months after the Colts traded for him. The trade probably contributed to the era of running backs being devalued.

11. (tie) Roy Williams, Amari Cooper to the Cowboys

It was too hard to decide between two big in-season receiver trades for the Cowboys. The first one came in 2008 for Williams, and it was a big deal at the time. Williams was formerly the seventh overall pick of the 2004 draft by the Detroit Lions and a Pro Bowler in 2006. In 2008 the Lions acquired a first-, third- and sixth-round pick for Williams, who was a bust with Dallas. He never had more than 600 yards with the Cowboys and was out of the league after the 2011 season.

Dallas’ 2018 trade for Amari Cooper was better. The Cowboys sent a first-round pick to the Oakland Raiders for Cooper. Cooper had 3,893 yards and 27 TDs in four Cowboys seasons before he was traded to the Browns in a salary-cap related move.

10. Jimmy Garoppolo to the 49ers

Despite legions of NFL analysts insisting the New England Patriots couldn't dream of trading Garoppolo, they had little choice. The Patriots still had Tom Brady and Garoppolo was about to become a free agent. So Bill Belichick called Kyle Shanahan and offered him Garoppolo for a second-round pick (Belichick was reportedly forced into the deal). Garoppolo had a solid run with the 49ers, who went 38-17 in his regular-season starts and won an NFC championship.

9. Minkah Fitzpatrick to the Steelers

The Steelers were questioned for their in-season trade for Fitzpatrick in 2019. They gave the Miami Dolphins a first-, fifth- and sixth-round pick for Fitzpatrick, a fourth-round pick and a seventh rounder. It turns out the Steelers were right, as Fitzpatrick has been perhaps the NFL's top safety since the trade. He was a first-team All-Pro in three of his first four Steelers seasons.

8. Carson Palmer to the Raiders

In 2011, Palmer threatened to retire rather than play again for the Cincinnati Bengals. The Bengals dug in, but eventually gave in and traded Palmer to the Raiders for a first- and second-round pick. Palmer had two nondescript seasons with the Raiders, but after the Raiders traded him to the Arizona Cardinals he had a good five-year run that included a Pro Bowl.

7. Bobby Layne to the Steelers

Imagine the reaction today if a future Hall of Fame quarterback was traded during the season. It happened in 1958, when the Detroit Lions sent Layne, then 32 years old, to the Pittsburgh Steelers. The Lions got Earl Morrall, who had a remarkable career ahead including an MVP with the Baltimore Colts in 1968, and two draft picks. The Steelers went 7-2-1 in Layne's starts after the trade, and Layne was a Pro Bowler in 1958 and 1959. He played five seasons with the Steelers before retiring.

6. Mike Haynes to the Raiders

This was the most complicated in-season trade. Haynes was holding out from the New England Patriots, and a deal with the Los Angeles Raiders was completed just after the deadline, Haynes went to federal court to challenge the ruling and eventually the trade was completed. The Patriots got draft picks, including a 1984 first-rounder that was used to trade up and select receiver Irving Fryar first overall. Haynes made an immediate impact, teaming with Lester Hayes for a devastating cornerback duo that led the Raiders to a Super Bowl XVIII win. Haynes was later inducted into the Hall of Fame.

5. Marshawn Lynch to the Seahawks

It didn't seem like a huge deal when the Buffalo Bills traded Lynch to the Seattle Seahawks for a fourth-round pick and a conditional pick that wound up being a fifth. It ended up being one of the biggest moves for a great Seahawks run that included a Super Bowl win. Lynch wanted a change of scenery and it worked out perfectly, with Lynch making four Pro Bowls with the Seahawks and setting the tone for one of the toughest teams of the early 2010s.

4. Jalen Ramsey to the Rams

Ramsey wanted out of the Jacksonville Jaguars, and perhaps forced the move by sitting out with a lingering back injury that suddenly was OK after the Los Angeles Rams traded for him. The Jaguars got two first-round picks and a fourth-round pick. Ramsey made a Pro Bowl in all four Rams seasons before he was traded to the Miami Dolphins, and was a key part of the Rams' Super Bowl LVI win.

3. Eric Dickerson to the Colts

This was a huge deal in 1987, in terms of number of players involved and the big headliner. It was a three-way trade in which the Los Angeles Rams sent Dickerson to the Indianapolis Colts, and the Buffalo Bills got linebacker Cornelius Bennett. Overall, the Rams got three first-round picks and three-second round picks along with two running backs. It involved 10 players, the second-largest in-season trade in NFL history. At the time, Dickerson was involved in a contract dispute with the Rams. In his first four full seasons with the Rams he led the NFL in rushing three times, including a historic 2,105-yard season in 1984 that is still the all-time record. Dickerson played five seasons with the Colts, rushing for 1,000 yards three times and leading the NFL in rushing in 1988.

2. Christian McCaffrey to the 49ers

We haven't seen the entirety of the return for the San Francisco 49ers on their big 2022 deal with the Carolina Panthers for McCaffrey, but it's looking really good. McCaffrey was traded last October and played just a few snaps in a loss to the Chiefs. The next week the 49ers started a 15-game regular-season winning streak. McCaffrey has scored in 15 straight games counting playoffs, two behind Lenny Moore's NFL record of 17 in a row. Carolina received second-, third-, fourth- and fifth-round picks for McCaffrey, which is fine for a rebuilding team. But the 49ers shouldn't have any remorse.

1. Herschel Walker to the Vikings

On Oct. 12, 1989, after Walker had played five games for the Dallas Cowboys, the Vikings and Cowboys pulled off a trade that has become synonymous with one-sided deals. The Cowboys traded Walker along with third- and 10th-round picks in 1990 and a third-round pick in 1991 to the Vikings for five players (linebackers Jesse Solomon and David Howard, cornerback Issiac Holt, defensive end Alex Stewart and running back Darrin Nelson, who was traded to the Chargers for a fifth-round pick) and a bunch of picks: first, second, and sixth rounders in 1990; first and second rounders in 1991; and first, second and third rounders in 1992. Yes, all for a running back. It's still the largest trade, in terms of players and picks, in NFL history.

You know how it turned out. Walker played three seasons with the Vikings and never topped 1,000 yards. Dallas used those picks to help build a dynasty that included three Super Bowl champs. The Vikings have still never won a Super Bowl.