Garrard, 36, was brought in two weeks ago and given a two-week roster exemption. He signed in March but was placed on the reserve/retired list two months later because his knees were giving him problems.
The Jets have rookie Geno Smith starting at quarterback, and he has led the team to 4-3 record. New York is one game back in the AFC East behind the New England Patriots.
“I was able to take the whole summer off and let my body heal. I started training a couple of months ago and my knee feels great,” Garrard said when he signed. “I’m sitting at home, watching games thinking, ‘Why am I at home? Why I am doing this to myself? I didn’t want to have any regrets one day."