GEORGETOWN, Ky. — Linebacker Keith Rivers joined the Cincinnati Bengals at training camp today after ending a 10-day holdout. The team's top pick promptly made a rookie mistake.

Rivers did the wrong exercise — jumping jacks — at the end of calisthenics, drawing a round of boos from teammates.

"It shows I haven't been here for a while," said Rivers, who participated in a mandatory minicamp in June. "I forgot how that rolls. Hopefully, next time I'll get that right."

Rivers, who signed a five-year contract Tuesday night, has some other catching up to do. He missed 12 practices, including the club's intra-squad scrimmage, besides meetings and film sessions.

"He looked like he did last time I saw him," coach Marvin Lewis said. "We'll see how we go through the week and see whether we play him, or how much. Unless I can find something major, I expect him to play some."

The Bengals open their preseason Monday night at the Green Bay Packers.

Rivers, the ninth pick out of Southern Cal, ran drills with the second-team defense, playing behind third-year player Brandon Johnson.

Terms of Rivers' contract haven't been disclosed.