The Minnesota Twins remain optimistic that Joe Mauer will return this season as he continues to recover from a concussion.

Terry Ryan and Ron Gardenhire said Mauer provided encouraging signs during a workout on Thursday.

"I'm holding out hope, as you know, that we ultimately can get him back on the field, so we're working toward that," Ryan said.

Mauer took a foul ball in the mask on Aug. 19. Mauer hasn't had an IMPACT concussion test for about a week, but he is expected to re-join the team Monday back in Minneapolis if all continues to progress.