German veteran Arne Friedrich says he had no choice but to retire.
"I would have loved to play a little more," told the Chicago Tribune.
"I guess I'm more sad than relieved. I didn't want to finish my career this way, but it was the only choice I had."
Friedrich was also extremely humble in deciding to end his contract with the Fire for the betterment of the club.
"As soon as I recognized that it wouldn't be possible to play again, I decided to ask the club to terminate my contract," he added.
"It was better for both sides. I didn't want to sit on the bench or in the stands and make the money but not be able to perform.
"It would (also) be better for the Fire. They could use the money to buy another player."