Chiefs put safety Bryan Cook on IR, activate LB Nick Bolton

KANSAS CITY, Mo. -- The Kansas City Chiefs exchanged one defensive starter for another from their injured reserve list, placing safety Bryan Cook on IR but activating linebacker Nick Bolton ahead of Sunday's game against the Buffalo Bills.

Cook, the Chiefs' seventh leading tackler with 35, injured his ankle in last week's loss to the Green Bay Packers. Cook made one of the Chiefs' biggest plays of the season in a Week 9 win over the Miami Dolphins after he took a lateral from a teammate who had recovered a fumble and returned it 59 yards for the deciding touchdown.

He will be replaced in the starting lineup by Mike Edwards, who joined the Chiefs this year as a free agent.

Bolton dislocated his wrist in a Week 7 win over the Los Angeles Chargers. He was placed on injured reserve after having surgery.

Bolton missed three games this season with a sprained ankle. Despite playing in only four games, he is 10th on the Chiefs in tackles with 28.

The Chiefs ruled out three other regulars for the game against the Bills: running back Isiah Pacheco, offensive tackle Donovan Smith and linebacker Drue Tranquill.