"This has been a very difficult decision," FitzSimmons said Wednesday in a statement released by his agent. "I feel like 2009 was one of the best seasons of my career, because I was so consistent, and was able to contribute in a variety of ways. If it wasn't for the concussions, I would not be retiring.
"It's frustrating because the rest of my body is still capable of playing at a high level in the NFL," FitzSimmons said. "However, given the seriousness of the risk associated with continuing to play, I have to listen to the advice the team has given me."
FitzSimmons, 29, is still feeling the effects of his latest concussion, said Chris Gittings, who along with Dan Hoeven represents FitzSimmons. They declined to say what symptoms Fitzsimmons is experiencing.
FitzSimmons entered the NFL in April 2003 as an undrafted free agent after earning NAIA All-America honors at Carroll College. He started 11 games as a rookie and played a total of 99 games in the NFL. FitzSimmons had 88 catches for 677 yards and five touchdowns, and in the past three seasons, he returned seven kickoffs for 113 yards and one score.
FitzSimmons and his wife, Allison, had a daughter in February. They have a ranch near Helena.
Copyright 2010 by The Associated Press