Updated

Orioles second baseman Brian Roberts thinks the headaches that forced him to miss the final six days of the season might have come from a self-inflicted blow to the head with his bat.

Roberts recalls knocking himself in the batting helmet after striking out in the ninth inning of a game at Tampa Bay on Sept. 27.

"In frustration, I whacked myself on the head with my bat. I had my helmet on. It's something I've done a million times," Roberts said. "I still can't tell you for sure if that was it. But that's the only thing that I can point to because that night and the next morning, I just didn't feel good."

Over the next six days, Roberts had headaches and symptoms of a concussion, including lightheadedness and a loss of balance.

"Stuff that hasn't been a whole lot of fun," he said.

It marked the end of a difficult season for Roberts, who played in only 59 games after spending several months on the disabled list with a back injury.