Bell, unhappy with diminshed role, asks for trade

Upon learning that he will used be as a backup following his team's bye week, halfback Tatum Bell has informed the Detroit Lions through his agent that he wants to be traded.

Bell, acquired in a trade from the Broncos during the offseason, entered the regular season as the starter. But last year's starter Kevin Jones has gradually been getting more playing time in recent weeks, and Bell's carries diminished in the second half of last Sunday's loss at Washington.

Bell's agent, Jeffrey Griffin, talked to the Lions late this week and expressed his concerns about his client's future in Detroit. With the trading deadline set for next Tuesday and teams in need of running backs, Griffin suggested a trade, although the team informed him he was a valuable part of the offense.

After the season, Bell is a free agent and wants to use this year to enhance his value. He has 44 carries for 182 yards this season in five games.

John Clayton is a senior NFL writer for ESPN.com.