BRADENTON, Fla. (AP) -- Trying to earn a job in the Baltimore Orioles' rotation, Jake Arrieta struck out five over four scoreless innings and allowed two hits Monday in a 4-3 loss to the Pittsburgh Pirates.
Arrieta, the Orioles' opening-day starter last year, became the first Baltimore pitcher to throw four innings this spring training.
''We didn't really talk about it much but I assumed that I'd go four, depending upon where my pitch count was at that point in time,'' he said. ''As far as what's in the tank, I feel like I could go six or seven innings right now. And that's a good feeling to have, to know, when there's that much left in the tank when you haven't thrown four innings yet. So, everything is good. Mentally, right where I need to be, and I'll be ready to go next time.''
Left-hander Zach Britton, another of the candidates, allowed one run in two innings of relief, giving up an RBI double to Josh Harrison in the seventh.
Pirates left-hander Jeff Locke, also competing for a rotation job, gave up two runs and eight hits in 3 1-3 innings. The 25-year-old pitched from the stretch most of the day. He threw his two-seam fastball to both sides of the plate, saw progress in his curveball and said his changeup was as good as it's been this year.
''I think I just have to keep attacking guys at this point,'' Locke said. ''When the time comes to bring the team north they're going to bring the best players that are going to give the team the chance to win every night. Obviously, that's something you want to be a part of, but I have to just keep going out and be myself and do the things I do well.''
Locke was relieved by 26-year-old right-hander Phil Irwin, who could win up in the rotation or the bullpen. He gave up one run and three hits in 3 2-3 innings with seven strikeouts.
Baltimore's L.J. Hoes hit a two-out, RBI single in the second and Lew Ford homered in the third.
Brad Hawpe, who played for Pirates manager Clint Hurdle in Colorado and is in camp as a non-roster invitee, homered in the eighth against Daniel Schlereth. The Pirates' Neil Walker, who was 2-for-16 coming into the game, doubled in the first inning off Arrieta.
NOTES: The results of an MRI on Orioles RF Nick Markakis' neck were not expected until Tuesday. ... Baltimore optioned OF Xavier Avery, LHP Mike Belfiore and RHP Zach Clark to Triple-A Norfolk. ... RHP Chris Tillman says his abdominal soreness is better, a day after being scratched from his scheduled start. ... RHP Luis Ayala pitched a scoreless fifth, his first exhibition game appearance. ... LHP Wei-Yin Chen's next appearance will come in a minor league game because Orioles manager Buck Showalter doesn't want him facing AL East opponents during the rest of spring training. ... Pittsburgh RHP Charlie Morton threw his first batting practice after undergoing elbow ligament-replacement surgery in June. He threw 12 pitches to two batters. ... RHP Jeff Karstens (biceps) threw a bullpen session and is to pitch two innings in a game Wednesday. ... Pittsburgh went without a DH for the first time this year, opting to bat Locke ninth.