MESA, Ariz. — A’s top pitching prospect A.J. Puk looked as if he was playing musical chairs on Sunday morning in the team’s clubhouse. On one side of the room, he was sitting at a teammate’s locker, staring into space. Some time later, he was sitting at his own locker, sipping out of his water bottle before placing it in a bin above where his jersey hangs.



He looked as if he didn’t want to be bothered. He was too locked in.



After Daniel Gossett was ruled out for Sunday’s contest at Hohokam Stadium against the Kansas City Royals with back tightness, Puk had to step in and fill that starting role.



His line for the day?



Two innings, no runs, no hits. The southpaw retired all six batters he retired, registering one strikeout.



The game ended in a tie, 4-4, but again, like much of spring training, Puk stole the show.



And, oh, remember A’s manager Bob Melvin talking about the left-hander having...