Tramaine Brock has agreed to a four-year, $16 million deal with the San Francisco 49ers.

Brock's deal includes $7 million in guaranteed money.

Brock's first start will come on Monday with Tarell Brown injured.

"He's gone from not playing, to being in the nickel, which is a part-time job, to now it's amped up another level that he's in there every play," defensive coordinator Vic Fangio said Friday.

The Indianapolis Colts have signed Chris Rainey.

Rainey was released by the Pittsburgh Steelers after a domestic dispute.

Rainey struggled at running back and the Colts will presumably use him as a returner.

The Tennessee Titans have signed John Skelton.

Skelton was most recently with the San Francisco 49ers

The Titans are without Jake Locker for the rest of the season.

Kyle Williams has been claimed by the Kansas City Chiefs.

Williams was released by the San Francisco 49ers on Tuesday.

Williams was a teammate of Alex Smith with the 49ers.

The Chicago Bears have signed Jay Ratliff.

Ratliff was released last month by the Dallas Cowboys.