PHOENIX -- Arizona Diamondbacks ace Zack Greinke left Tuesday night's 4-3 loss to the Philadelphia Phillies after two innings with tightness in his left oblique.
Greinke, in search of his 11th win, hit a bases-loaded sacrifice fly to score a run in the second inning and left after a few warm-up pitches before the start of the third. He said later that he figured he hurt himself on that swing.
Diamondbacks manager Chip Hale said there was no way he was going to risk his prize pitcher worsening the injury.
"It's something maybe he can maybe miss a start, possibly not miss a start; possibly at worst, maybe 15 days on the DL," Hale said. "You never know. But if you go out and really yank it bad, you're talking about a month or two, so we'll hope for a best-case scenario."
Greinke allowed a run in the second inning on consecutive singles. Then, in the bottom of the inning, Arizona loaded the bases with no outs, but the only run the Diamondbacks scored was on Greinke's sacrifice fly to left.
When he walked back onto the field to start the third, he looked at the dugout and called for the trainer.
After a short huddle with umpires, Greinke went into the dugout to apply some heat ointment and emerged a moment later.
He threw a few warm-up pitches off the mound but didn't feel any better, and he left the game.
Greinke said he didn't want to come out of the game but realized later it was the right thing to do.
"I more than likely would have hurt myself a lot worse staying," he said.
Greinke hasn't missed a start since 2013. He was 7-0 in his previous eight starts.
"I was pitching pretty good for a while and felt really good today," he said. "Hopefully, it's nothing major -- we'll find out more in the next couple of days -- and hope it's nothing much at all and [I] just continue pitching good."
Greinke signed a six-year, $206.5 million contract with the Diamondbacks during the offseason. He entered the game 10-3 with a 3.61 ERA.
In other Diamondbacks injury news, left-hander Robbie Ray said he was fine and would be ready for his next scheduled start on Sunday at home against the San Francisco Giants. Ray left Monday night's 8-0 loss to Philadelphia with a blister on his left middle finger.
The Associated Press contributed to this report.