CHESTER, Pa. – It may not have seemed like much when Krystian Witkowski entered the Philadelphia Union’s last Reserve League game in the 87th minute.

But for Witkowski, it was a big deal. A very big deal.

To that point, the rookie hadn’t even worn his jersey, let alone seen any kind of minutes for the Union. In fact, after suffering a concussion at the very beginning of his first professional season, he wasn’t even sure if he would ever be able to play soccer again – at any level.

“It was the worst thing that could have happened,” Witkowski told MLSsoccer.com after a recent training session at PPL Park. “It’s like your identity is taken away from you.”

It happened back in March when Witkowski went up for a header in training and collided with a teammate. A couple of days later, after being selected to the 18-man roster for the Union’s game at Chicago on March 24, he began to feel the effects of the collision.

On the plane to the Windy City, he got severe headaches and, after alerting the medical staff of his issues, was diagnosed with a concussion after returning to Philly.

“I’ve been hit a lot harder,” Witkowski said. “That’s why some of the doctors think it might have been the airplane with the pressure that intensified everything.

“I thought it was the best thing to happen in my life, getting called up to the 18. But it might have been what contributed to this.”

READ: Union's Lahoud wants silverware

In the six-and-a-half months since that fateful trip to Chicago, Witkowski has been working with the training staff to recover. It hasn’t been easy.

For a while, he spent many days lying in bed with terrible headaches. He struggled with simple things like walking up stairs. Sunlight bothered him. He couldn’t go out socially with teammates if the music was too loud. He lost weight. He became overly aggravated with people. He was depressed.

“It’s been an extremely tough year – probably one of the toughest years of my life” Witkowski said. “I’ve never been out of soccer this long.”

The Supplemental Draft pick out of Marist still participated at practice, but mostly juggled and passed with teammates off to the side, avoiding any kind of contact drills. Even jogging became difficult as he said running “for five minutes was like me doing 100 laps.”

But after a lot of tests and staying in line with the league’s strict concussion protocol, Witkowski was finally cleared by his doctor to play two weeks ago. That led to a brief Reserve League appearance on Friday, which he called, on Twitter, “one of the best days of my life.”

“It puts things into perspective,” he said. “You see how fragile life is.”

READ: MacMath has season goals in sight

Knowing all about that fragility, Witkowski has been taking online classes at Marist, doing a lot of reading and playing mental games with Michael Farfan, one of his best friends on the team, to “keep the brain going.”

Still, he hopes to play professional soccer next year and is especially happy to know that the concussion is not a career-ending injury. But he also knows it might be a lot to ask to remain on the Union roster in 2013.

“I don’t think [Union manager John Hackworth] has seen me play since March, besides juggling on the sideline,” Witkowski said. “I think it will be extremely tough to be back here next season. I would love when I’m fully healthy to be invited back to preseason to show my worth. That would be the ideal situation for me.”

Even if he doesn’t return to Philly, he’s grateful for everyone on the team for helping him get through what he called a “very scary” situation. And with the concussion symptoms now in the past, he’s eager to build off his recent Reserve League debut and continue to play the sport he loves.

“If you put me out there, I’ll still play as hard as I do,” he said. “It’s just how I play and how I’ll always play.”

Dave Zeitlin covers the Union for MLSsoccer.com. E-mail him at djzeitlin@gmail.com.