The veteran second baseman explained Monday that he missed the last six games of the season for concussion-like symptoms after hitting himself in the helmet with a bat.
Roberts, who missed much of the season with injuries, thinks it happened last Monday, after a ninth-inning strikeout against the Tampa Bay Rays.
"In frustration [after a strikeout], I whacked myself on the head with my bat in the ninth. I had my helmet on," Roberts told reporters. "It's something I've done a million times, but 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. So it's been going on since then."
Roberts battled injuries most of the season and appeared in just 59 games. He was scheduled to have a CT scan to determine if there was another possible cause for the concussion-like symptoms.
"I just have some lack of balance and some headaches, and just stuff that hasn't been a whole lot of fun," Roberts said. "It's a lesson to myself, a lesson to the kids to not do that, no matter how frustrated you are."