He injured his left leg while running in preliminary heats in the 200 during the US trials in July. He had already qualified for the 100, where he is expected to contend with world-record holder Usain Bolt and Asafa Powell, who held the record before Bolt.

Gay pulled out of a race in London on July 25, saying he wanted to rest to ensure he was healthy for the Olympics. He had said earlier this week that he would be ready, and looked comfortable running the 100 for coach Jon Drummond.

Gay said a more detailed MRI had discovered a slightly strained tendon after the trials that was worse than originally diagnosed. He admitted having doubts about whether he would be able to get back in time for the Games. Now, he said he's "pretty close" to where he was before the injury, noting that he might have run the 100 faster had he done a second set of sprints after being fully warmed up.

Gay said his recovery had gone well. "I've gotten a lot of rest. I mean, everyone knows I haven't raced since nationals, but I think that was good for me because even if I would've ran the 200 I'd have been really fatigued," he said.

"I've seen a lot of people from the US not running as fast as they were and a lot of people's bodies are tired, so I think this rest really did me well."