The Raiders (3-10) also cut backup fullback Owen Schmitt and promoted cornerback Chimdi Chekwa from the practice squad as they plan to get a better look at young players down the stretch of another disappointing season.
McClain had been suspended for two games on Nov. 30 for conduct detrimental to the team after a practice run-in with coach Dennis Allen. McClain did not practice Monday and is not required to return to the team until he meets with Allen, who was in Texas on Monday for his father's funeral. The team says Allen will discuss McClain's role with him after he returns.
General manager Reggie McKenzie declined to comment on the moves and Allen will not be available to discuss them until he returns to practice on Wednesday.
But players said the news that Bartell was gone took them by surprise.
"I came in this morning and heard everybody talking about it. I didn't believe it at first, but got in here and didn't see him in here," cornerback Michael Huff said. "Definitely, definitely tough, but obviously part of the business."
Bartell was signed to a one-year contract worth $3 million in the offseason after missing all but one game in 2011 with St. Louis because of two neck fractures.
Bartell began the season as the starter but broke his left shoulder blade in the season opener. He returned to the lineup Nov. 11 in Baltimore and started the past five games, playing 95 percent of the defensive snaps. For the year, Bartell allowed 18 catches on 28 throws in his direction for 295 yards and four touchdowns, according to Pro Football Focus. He had no interceptions.
He was benched briefly in the first half on Dec. 2 against Cleveland before returning in the second half when Phillip Adams sustained a concussion.
The Raiders are now without both cornerbacks who began the season as starters with Shawntae Spencer on injured reserve with a sprained right foot. Pat Lee, who started seven games earlier this year, was released last month, leaving converted safety Huff as the only player on the roster who has started at cornerback this year.
Adams got additional playing time the past two weeks as coaching staff wanted to see what he could bring to the team. He played well in his brief time, intercepting two passes, including one last week from Peyton Manning. Adams allowed two catches on six throws his direction for 6 yards, according to Pro Football Focus.
"I just come in and do what I'm supposed to do," Adams said. "You can't worry about anything else. It's a business. You can't worry about what's going on. I just try to approach the game how it should be approached and go and work hard every day because your teammates rely on you. That's what I plan to do."
Chekwa was a fourth-round pick by the Raiders in 2011 and played four games as a rookie, starting once, before missing the rest of the season with a hamstring injury. He did not make the 53-man roster out of training camp this season as the new regime headed by McKenzie and Allen wanted to look at other options at cornerback.
But Chekwa will finally get a chance to show what he can do in the final three games this season.
"I'm not really worried about people watching me or them making a decision on what they want to do in the future," Chekwa said. "I just want to play football."
Schmitt played sparingly in his first season with Oakland, getting his most action when Marcel Reece shifted to tailback following injuries to Darren McFadden and Mike Goodson. With McFadden and Goodson healthy again and the Raiders having signed fullback Jamize Olawale from the Dallas Cowboys practice squad last week, Schmitt was expendable.
McFadden practiced after leaving last Thursday's game when he re-aggravated a right ankle injury. ... DT Richard Seymour returned to practice for the first time since missing five games with a hamstring injury. ... S Tyvon Branch missed practice with injuries to his ankle and neck. ... The Raiders also re-signed S Akwasi Owusu-Ansah to the practice squad.