OAKLAND With the way right-hander Jarrod Parker was pitching Saturday, A's manager Bob Melvin started his post-game remarks by saying he half-expected to still be in the dugout watching Parker and Cardinals right-hander Adam Wainwright trade zeroes, as they did for the first three innings.
Instead, Melvin and the A's were left wondering about Parker's status after he left their 7-1 loss to St. Louis in the fourth inning after throwing a pitch and going to the ground grabbing his right hamstring.
The A's announced Parker, 24, left because of right hamstring tightness. Melvin said the A's were hoping it was nothing more than a cramp.
"We'll see (today) how he's feeling and then if everything feels OK, see how he feels in his bullpen and then proceed from there," Melvin said. "But you know a lot more (today)."
Parker has been the A's second-best starter over the past month behind Bartolo Colon he entered Saturday's game 4-0 with a 2.34 ERA in his last six starts and retired 11 of the first 12 hitters he faced against the Cardinals.
With two outs in the fourth, Parker threw a pitch that Allen Craig hit for a double and went down grimacing and grabbing the back of his leg. An A's trainer stretched out Parker on the field, and he threw several practice pitches before walking off.
"It's kind of early, but I think it's just tight and we'll be able to assess it in the coming days," Parker said. "I just threw the pitch, and it just kind of got tight on me."
Parker said he hadn't felt any discomfort before the pitch, and he didn't have any tests after leaving the game. Melvin said Parker floated the idea of staying in and trying to finish the inning.
"But he still felt it, and it's not a prudent thing to do," Melvin said. "The unfortunate thing was that might have been as good of stuff as he's had all year."
Parker, who has improved steadily since an 0-4 start in April, agreed "everything was working good early," allowing him to get ahead of the St. Louis hitters with a variety of pitches and record quick outs. He threw 36 pitches before facing Craig to match the pace of Wainwright, who allowed only a single to Derek Norris through three innings.
Parker's exit led to an impromptu appearance by long reliever Jesse Chavez, who retired Matt Holliday to end the fourth but allowed two runs in the fifth. Chavez started the fifth by walking Matt Adams and hitting David Freese, and both scored.
After allowing the first two hitters to reach again in the sixth, Chavez gave way to Jerry Blevins, who allowed an RBI single to Holliday and then missed over the plate with his first pitch to Adams, who hit it into the right-field seats for a three-run homer and 6-0 Cardinals lead.
Chavez, a hero of the A's 18-inning win over New York on June 13 for his 5 2/3 innings of scoreless relief, has allowed at least one run in three of his four appearances since. He said after Saturday's outing he went back to the clubhouse to watch video and found a mechanical "tic today that threw me out of rhythm." He did not blame his abrupt entrance.
"That's the life of the bullpen," Chavez said. "I still have to do my job."
A six-run lead was more than enough for Wainwright, who recorded his 11th win tied for the most in the National League with Jordan Zimmermann of Washington and fourth complete game of the season, one short of his season high.
Wainwright struck out eight and didn't allow a runner past first base until the eighth, when Josh Donaldson led off with a double and scored on a single by Josh Reddick.
Melvin, meanwhile, was left to wonder if it might have been one-half of a fine pitchers' duel. Parker said his practice pitches before leaving the game "felt all right, but I don't think it would've been the smartest thing to try to gut through it. We made a good decision.
"We both might have got out with no-decisions," Parker added with a grin about him and Wainwright. "Who knows?"