Harvin has missed Minnesota's last two games because of another episode with migraine headaches, calling the experience "a bad two weeks," but was back at practice Thursday and said Friday he's feeling better.
Harvin said last week's absence was precautionary, while doctors advised waiting to see how his body reacted to new medication.
"We covered pretty much every base so we've got a plan to prevent it, we've got a plan if it comes, and we've got a plan if it gets real bad," said Harvin, who visited a branch of the Mayo Clinic in Scottsdale, Ariz., last week to see a specialist who previously treated former NFL star Terrell Davis.
Davis also dealt with the condition during his career.
Harvin met with interim coach Leslie Frazier and team owner Zygi Wilf to talk about his condition and find "the best doctor we could possibly find."
Frazier praised Wilf for his care.
"It's more our ownership just being concerned about our players as people, as opposed to just the fact that he can run fast and catch a ball," Frazier said. "They wanted to do something that was going to be beyond football and whatever that took, they wanted to get that done. If it meant he wasn't going to play again this year, they would have sacrificed whatever needed to happen to help him be able to live a life hopefully without going through what we've seen him experience."
Harvin said he tries not to get frustrated by the unpredictable and debilitating nature of the migraines.
"I go to the doctor and I see people who can't even get out of the bed every single day," Harvin said. "I see I have it good. I realize I'm blessed. It's just something that's going to happen. Unfortunately, you can't eliminate it from happening, so hopefully we can slow it down."
Harvin said he's not concerned about regaining his conditioning.
"I looked pretty good. A lot of the players say I look more explosive now than I did before I left," he said, smiling. "It was just good to get out there and not have a foggy head or a slight headache."
"It's great having him back out," Frazier said. "It energizes the rest of our players. You know how dynamic he is as a player, and his frame of mind is so good. He looks good. He's moving around exceptionally well. Just good for our team."
Adrian Peterson (ankle, knee) was one of five players held out of practice Thursday and Friday, but Frazier said this is precautionary and that he expects the All-Pro running back to play against the Bears.
Quarterback Brett Favre sat out again, too, and Frazier said if he can't participate Saturday he'll likely be ruled out for the second straight game.