The Red Sox get Zach Stewart and Brent Lillibridge, but will pay more than $5.5 million of Youkilis' salary. (Getty Images)

Kevin Youkilis returned to the Red Sox lineup Sunday, for the first time since last Wednesday.

And for the last time.

The Red Sox have reached a deal to trade Youkilis to the White Sox, sources told CBSSports.com's Jon Heyman on Sunday afternoon. The Red Sox will get pitcher Zach Stewart and utility man Brent Lillibridge, and will also pay a little more than $5.5 million of the remaining $8 million on Youkilis' contract.

Talks between the Red Sox and White Sox heated up Saturday, sources say, with the two teams haggling over how much of the contract that the White Sox would pay.

The Red Sox have been determined to trade Youkilis, who lost his full-time job with the emergence of rookie third baseman Will Middlebrooks. Talks heated up in the last few days, with the Indians, Dodgers and Pirates also showing some interest.

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The White Sox always made the most sense, though, because they have the biggest need at third base. Entering play Sunday, White Sox third baseman had combined for a .466 OPS, easily the worst among the 30 teams.

Youkilis, who was a big part of Red Sox championship teams in 2004 and 2007, isn't nearly the player he once was. But he still had a .670 OPS entering play Sunday, and he went 2-for-4 with a triple in what turned out to be his Red Sox finale.

Youkilis' presence in the lineup Sunday was something of a surprise, but it provided him with an emotional Fenway Park send-off. When Youkilis was removed for a pinch runner after a seventh-inning triple, he received a huge ovation.

Even though Youkilis hasn't been very good lately, he still should be a significant improvement over Orlando Hudson, the player he'll replace in the White Sox lineup.

Youkilis didn't cost the White Sox much. Stewart is a 25-year-old right-hander who isn't nearly the prospect he once was with the Blue Jays. He has a 5.92 ERA in 31 big-league games, and was just sent back to Triple-A Charlotte. He once threw as hard as 95 mph, but recently has only been clocked at 90-91. Stewart came to the White Sox last year in the Edwin Jackson trade.

Lillibridge is a 28-year-old utility man.

Even now that Youkilis is on the way out, the Red Sox will be active on the trade market, possibly as both a buyer and seller.

With Jacoby Ellsbury and Carl Crawford both on the way back, the Red Sox soon will have a glut of outfielders, and Cody Ross and/or Ryan Sweeney are expected to be among those made available in trade.

Dealing Youkilis has been a more urgent concern. Besides simply wanting to play Middlebrooks every day (and to avoid using Adrian Gonzalez in the outfield), the Red Sox don't want Youkilis to become even more of a distraction than he already has been. The relationship between Youkilis and manager Bobby Valentine has never been good, and late Saturday night Youkilis' brother Scott took to Twitter to call Valentine "a joke."

Youkilis has spent his entire career with the Red Sox, the team that drafted him in 2001. Since 2004, when Youkilis made his major-league debut, only David Ortiz has played more games for the Red Sox than Youkilis.

Sunday was Youkilis' 953rd game with the Red Sox. And his last.