MESA, Ariz. -- Corey Koskie was the happiest player in Cubs camp on Saturday, simply because he could take ground balls.

Koskie, 35, is trying to make a comeback from a concussion he suffered in July 2006. He has not played in the Major Leagues since, and it wasn't until recently that he found a medical team that could help him even consider returning to a playing field.

On Saturday, he not only passed his physical with the Cubs, but also participated in drills with strength coach Tim Buss and athletic trainer Mark O'Neal.

"It's nice to go out there and run around and break a sweat," Koskie said.

A non-roster invitee with the Cubs, Koskie is a few days from actually getting in a game. He was on Team Canada's roster in the World Baseball Classic but did not play, except for four innings in exhibition games before the event began.

"My first at-bat with Team Canada, I got hit," Koskie said. "I got hit on the shoulder, then I had to score from first [on a double]. That was a pretty special moment just to be like, 'I'm back, maybe I can do this again.'

"It took longer than anybody expected. Now I'm back to the life I had before the injury. If this doesn't work, whatever happens, I can put that part of my life behind me and move on."

It's been 2 1/2 months since he's had any of the symptoms associated with the concussion, which occurred while trying to catch a popup by Cincinnati's Felipe Lopez at Miller Park. Then the Brewers' third baseman, Koskie fell but never hit his head on the ground.

"I went running to the spot where I thought the ball would be, looked up and fell backward," he said.

When the freak accident happened, Koskie would try to drive, but his head hurt too much and he'd get dizzy. He'd lay down, exhausted, and doctors told him he was sleeping too much.

"I said, 'I am because my head hurts,'" he said.

He was nauseous, dizzy, and felt a little behind everybody and everything.

"It'd be like if you followed a kid with a video camera and you're focusing through the little screen and following him around, but it's right here," Koskie said. "You're there, but you're not quite there.

"It's like sitting in an office and looking outside and there's a window separating you from the outside. It's cold and windy, and you're there but you're not there. It's kind of hard to explain.

"It's almost like being drunk. Your depth perception, your cognitive skills are off."

He talked to other athletes, particularly hockey players who had suffered head injuries, for help, and saw several neurologists. It took 2 1/2 years to find the right medical team to help, led by physical therapist John Groves of Minneapolis.

"Whatever he did helped me," Koskie said.

One of the first steps was to straighten his neck. Koskie had been going around a little crooked. After some manipulation and therapy with Groves, Koskie started exercising in early January, then worked out at the Metrodome, then trained in Ft. Myers, Fla., on a back field of the Twins' complex. Team Canada was the next step. He's making progress.

"The last eight weeks, it's been an evolution of its own," Koskie said. "If you had asked me eight weeks ago if I would've been in this situation, I don't know if I could've told you I would be."

He has no expectations. Whatever happens now, happens. He doesn't know what the normal recovery period is for someone who suffers a concussion. As Koskie said, he's from a small town, Anola, Manitoba, and didn't study neurology. One thing he has learned is that each case is individual to each person. Some football players collide helmet-to-helmet, and bounce back much faster than he has.

If there's one thing he would've done differently, it's not push himself to try to exercise through his symptoms.

"That was one of my biggest mistakes and one of the key factors and reason this thing held on for so long," he said.

Head injuries are nothing like knee injuries.

"My biggest thing is I'm healthy," Koskie said. "I'm able to try to do this, I'm able to put on a uniform. That's the biggest thing is I cleared medical exams. Everything else is a bonus."

Taking some grounders never felt so good.