Doolittle (shoulder) said he will begin playing catch Friday, Susan Slusser of the San Francisco Chronicle reports. This is a big step in Doolittle's progression, as he has thus far been limited to sock throws since getting a platelet-rich injection in January. He hopes to join the A's by late April, but it won't be surprising if he isn't ready until May. Tyler Clippard still figures to work as the closer until Doolittle is ready.