Orioles second baseman Brian Roberts, who hasn't played since incurring concussion symptoms after sliding headfirst into first base May 16, has been shut down from baseball activities for at least two more weeks.

Roberts was re-examined by sports concussion specialist Dr. Michael Collins in Pittsburgh on Tuesday, and, though he can begin cardio and weight work soon, the leadoff man will not pick up a baseball for two more weeks, at the earliest.

"I wouldn't call it bad news," manager Buck Showalter said. "We knew the process that we were going to have. We'll follow the doctor's suggestions."

Roberts played in just 59 games last year because of myriad injuries, including a herniated disk in his back and a late-season concussion suffered when he hit himself in the helmet with a bat. The two-time All-Star has played in just 39 games this year and is batting .221 with three homers and 19 RBIs.

On the 15-day disabled list, he could join the team on this homestand for a few days, then return to Sarasota, Fla. Showalter has not ruled out Roberts' returning to the Orioles before the All-Star break.