Chiefs' Jeff Allen needs elbow injury

KANSAS CITY, Mo. -- The bad injury news continues to pile up for the Kansas City Chiefs.

Coach Andy Reid on Friday said offensive lineman Jeff Allen needs elbow surgery and is not likely to return this season.

Also, rookie running back De'Anthony Thomas has been ruled out for Sunday's game against the Broncos in Denver because of an injured hamstring.

Allen started at right tackle in the season opener against Tennessee. He began training camp as the team's left guard but switched positions after Donald Stephenson was suspended for the season's first four games because of a violation of the NFL's policy on performance-enhancing substances.

Allen's spot at right tackle on Sunday will be filled by veteran Ryan Harris, who signed with the Chiefs on the eve of training camp. The starter in Allen's original spot at left guard, Mike McGlynn, joined the Chiefs in late August after being released by Washington.

If Allen misses the remainder of the regular season, he would be the third starter lost for the year from the Titans game. Linebacker Derrick Johnson and defensive end Mike DeVito each ruptured an Achilles tendon.