Athletics pitcher Drew Pomeranz surrendered one earned run on four hits and one walk in four innings while striking out five in his team's 4-0 loss to the Mariners Wednesday.

"I’m trying to fill up the (strike) zone," Pomeranz said after the outing, per the Contra Costa Times. "I got the ball a little up in the first inning. After that there were a lot more low strikes. I felt pretty good. I just need to build up stamina for a higher pitch count."

Pomeranz has been a strikeout machine in camp, racking up 15 punchouts against three walks in nine innings over three spring appearances. His only blemish Wednesday came on an RBI single in his final inning of work.

Manager Bob Melvin called Pomeranz "in the mix" for a rotation spot after the outing. "He has been from the beginning," Melvin said.

Pomeranz is competing to open the season in the Oakland rotation after going 5-4 with a 2.35 ERA and 64:26 K:BB ratio in 69 innings last year.