Phegley was at Minute Maid Park for Saturday's game, but Melvin said he could be unavailable for several days given he has to pass the concussion test before he would be cleared to play.
Phegley joins fellow catcher Stephen Vogt -- who suffered a groin injury on Sept. 6 -- on the injury report. Vogt went through full pregame work on Friday and Saturday and could play Sunday, according to Melvin.
Carson Blair, who caught Friday's game and went 1-for-4 with a single, was behind the plate Saturday.
Chandler Rome is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.