Over the next few months, Roberts did everything from following a pen back and forth with his eyes to moving his head side to side while focusing on a distant, fixed point. By June he was fielding balls tossed from behind him over one shoulder, then another.

After another initial round of headaches, and as Roberts eased into light baseball activity in July, the intense reaction to ordinary activities began gradually to lessen.

"None of this was easy, but it was nice to see a light at the end of the tunnel," Roberts says.

Fits and starts

Relaxed during an interview in his Baltimore rowhouse last month, Roberts was all but giddy to report that, for the first time since the Tampa incident, he'd felt no symptoms for two weeks.

"Baseball or not, it's wonderful to have a normal life," the 2009 Oriole MVP said, taking periodic sips from a 32-oz. designer water.

He had even walked his dog in Sarasota without pain, though he wasn't sure that constituted the ultimate test. "Luckily, he's fat and slow," he said.

Roberts has learned he has innate susceptibility to vestibular concussion, and not because he's soft on the head or in it. He has always had problems with carsickness, and recent research shows a link between that trait and a high prevalence of the injury. (Attention deficit disorder and migraine-headache problems are two other such traits.)

He has also learned that, unlike, say, a torn ligament or an ankle sprain, concussions are so complex it's impossible to predict the healing period.

But some conditions prolong recovery, and Roberts isn't shy on those. They're what make him who he is.

For several days after he was injured in Boston, he stayed with the Orioles, but the act of sitting in the dugout and trying to follow the ball made him ill. Collins told him to get away, so he left the team. He didn't see friends like Nick Markakis, Adam Jones and Jeremy Guthrie for months.

Roberts lives in Canton, not far from Brewer's Hill, and he and Diana enjoy walking the streets, attending church nearby and chatting with fans. When they kept asking how he was doing, Collins advised him to leave Baltimore. He and Diana flew to Sarasota and didn't return until last month.

The research, Collins says, is clear: The less strain on a concussion victim, the better.

"There are two things you don't want to do [as a patient]. Number one, don't get hit again. Number two, don't increase the demand for energy. You can cause a lot of problems by overtaxing the brain."

That includes watching the O's on TV — which Roberts did every day for six weeks, until he says it became too emotionally painful. It includes explaining his condition on the phone — which he did regularly until it triggered such headaches he had to delegate Diana as his liaison. It includes taking batting practice and ground balls — which he started doing, gingerly at first, in June and continued to do, off and on and with increasing intensity, through July and August, when it didn't cause too much pain.

Quite possibly to his own detriment, Roberts never gave up on the idea of playing in 2011. One day, a light workout would leave him feeling fine. The next it would leave his head screaming. If he felt fine the next morning, Collins gave him the OK to try again.

The goal was to bank more good days than bad, something he and Collins were starting to achieve by mid-September. But by that point it was clear Roberts wouldn't pass the necessary health tests before the baseball season ended. So doctors shut him down.

What's left

Sometimes, when everything you know and count on is taken away, it's interesting to see what's left.

When Roberts was able to practice last summer, he did so at the team's training complex in Twin Lakes, Fla., alongside the young minor leaguers of the Gulf Coast Orioles. They asked what seemed like a million questions, the way he once did of B.J. Surhoff, Mike Bordick and Cal Ripken.