Orioles second baseman Brian Roberts was not cleared Tuesday to begin baseball activities during his third appointment with concussion specialist Dr. Michael Collins, a development that pushes back his return to the team's lineup until late July at the earliest.

Roberts, who hasn't played since May 16, when he started getting headaches after sliding headfirst into first base to beat out a game-starting infield single against the Boston Red Sox, will be evaluated in two more weeks.

"Some progress, but Dr. Collins is going to re-evaluate in two weeks," Orioles president of baseball operations Andy MacPhail said.

Roberts has improved, but he's still experiencing concussion symptoms, including exercise-induced headaches. The second baseman is permitted to do some conditioning activities going forward. However, he's on a limited program.

Roberts has had two concussions in the past 61/2 months. He has played in just 39 of the Orioles' first 71 games after missing 103 games last season because of a herniated disk in his back and a concussion sustained when he hit himself on the helmet with his bat after striking out.

Orioles manager Buck Showalter spoke to Roberts in the lobby of the team hotel Monday night. However, Roberts did not appear at PNC Park and he's scheduled to fly back to the team's spring training complex in Sarasota, Fla., on Wednesday morning.

"I just got the timeframe more than anything," Showalter said. "As far as what's going on between now and then, it probably wouldn't be too much different from what he's been doing, I would think."