ST. LOUIS -- Injured catcher Ryan Doumit will begin a rehab stint at Double-A Altoona on Tuesday, where he is expected to play in three games before returning to Pittsburgh on Friday.

If all goes as planned, Doumit, who fractured his left thumb on May 13, will then be taken off the disabled list in time for Friday's game. That will be less than the expected minimum four-week recovery time that was initially given.

Doumit spent Monday serving as the bullpen catcher during the game. It marked the second straight day in which Doumit has taken high-velocity throws behind the plate. Like he did on Sunday, Doumit reported no pain after Monday's work.

Doumit has also been taking consistent batting practice from the left-handed side of the plate and will likely hit primarily -- and maybe even exclusively -- left-handed during the rehab games, manager John Russell said. Because more pressure is put on Doumit's thumb swinging right-handed, he hasn't progressed past hitting soft toss or off the tee from that side of the plate.