The midfielder found playing time hard to come by in 2012, and will now join the playoff-chasing Chicago side.
Thompson came to the Colorado in a Jan. 2010 with New England, and appeared in a total of 75 games for the Rapids (40 starts), scoring five goals and adding four assists. He was also a member of the 2010 MLS Cup-winning team.
"Wells is a steady, dependable player that has proven himself in MLS," said Fire head coach Frank Klopas. "He will provide additional depth and coverage on the wing and in the midfield as we continue to make our push for the MLS Cup Playoffs."
Chicago currently sits in fourth place in the Eastern Conference, while Colorado is on the way out of the Western Conference playoff chase, eight points away from the fifth and final spot.
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