President and General Manager Dave Dombrowski praised Trammell, calling him "dedicated, hard-working and respected," the Detroit Free Press reported.
"However, for the Tigers to reach the next level, I feel it is appropriate to make a change at this time," Dombrowski said.
Trammell, the club's longtime short stop, spent three seasons as manager. In 2004, the club won 73 games, a big improvement over the previous season's 43.
But this season, the Tigers in August were just under .500 and then went into free fall. The team ended the year 71-91.
The team said that Trammell has been offered the position of special assistant to the general manager.