MINNEAPOLIS -- Percy Harvin's migraine headaches have been a riddle that no one has been able to solve.
After another battery of tests last week, and a promising 2010 preseason debut, Harvin hopes he is getting closer to figuring out a debilitating medical condition that has plagued him for most of his life.
The Minnesota Vikings receiver had two catches for 30 yards and took two big shots to the head Saturday night in a preseason victory over Seattle, the first time he's played this year after being stricken by migraines for most of training camp.
"I felt great," Harvin said after the game. "Just glad to get back out there with my teammates and work some of the rust off. I've got a lot of work to do, conditioning-wise, but it felt good to get out there."
Harvin has barely practiced this month while dealing with the death of his grandmother and a string of headaches that have been maddeningly random and devastatingly severe. No one knows exactly when they're going to occur or what triggers them. Even more frustrating, doctors and trainers have been unable to come up with a treatment to neutralize them.
The Vikings have gone to great lengths to try to identify the causes and understand the problem.
"It's kind of a tenuous thing," coach Brad Childress told The Associated Press last month. "What can exacerbate migraines? Stress? Check. Fatigue? Check. Head or neck trauma? Hmmm."
Despite playing a sport that doesn't exactly help his condition, Harvin said he has no plans on making a career change.
"It's been rough, but it's life," Harvin said. "I don't want the easy way out sometimes. It's life, I'm dealing with it. I finally got back and it's good to be back out here with my teammates."
He missed one game last year because of the headaches and missed several practices in the playoffs. But teammates and coaches got their first real glimpse of how serious they can be on Aug. 19, when Harvin vomited and collapsed on the practice field.
He was taken by ambulance to a local hospital and spent the night. More tests ensued and Harvin surprisingly suited up for the game Saturday night despite not practicing all week.
"I did a test [Friday] night and they found some things that we think was the main cause of it," Harvin said. "We're feeling really confident. I know we said that a couple times, but I think this time we found what the main cause was. I'm not saying I'll never get a headache again, but hopefully we can slow it down a little bit."
The Vikings know they have to be cautious in their optimism, but they were treating that development as good news for the reigning offensive rookie of the year.
With Sidney Rice out for possibly the entire first half of the season with a hip injury, Harvin's importance to the offense has grown exponentially. He is Brett Favre's favorite target and a valued weapon for offensive coordinator Darrell Bevell, who can line him up at receiver or running back.
"It was a good start," Favre said of Harvin's first game. "Percy's a football player. I'm not surprised at anything he does."
"He didn't seem any worse for the wear," Childress said. "He took a couple of pretty good licks."
Harvin knows that's going to come with the territory and prepared himself for it.
"Everybody looks for that first contact to get hit, to feel part of the game," he said. "I was looking forward to getting hit."