PHOENIX -- Zack Greinke knew something was wrong from his first warm-up pitch before the third inning.
His side didn't feel right. The D-backs starter left the field, went into the dugout tunnel to apply heat to it, and then tried to warm up again. But when the discomfort was still there, Greinke exited Tuesday's 4-3 loss to the Phillies with left oblique tightness after just two innings.
"Definitely something was not perfect, something was wrong," Greinke said. "At the time, I didn't know if it was a good idea or not to do what we did but afterward, it was probably the right move. I more than likely would have hurt myself a lot worse."
Greinke said he believes he sustained the injury during his at-bat in the bottom of the second, when he hit a sacrifice fly to left.
He threw two pitches warming up for the next inning before asking home plate umpire Pat Hoberg if he could leave the field to heat up the tight area. Greinke said he has had tightness in areas before and applying heat can sometimes relieve the issue.
Greinke returned and threw three more warm-up pitches at what he called "50-to-70 percent" when he returned to the mound in front of manager Chip Hale and head trainer Ken Crenshaw. They determined it would be best for the right-handed ace to leave the game.
"I always have stuff get tight or whatever, but this was a little different," said Greinke, who had won seven of his previous eight starts entering Tuesday.
Hale said he is not sure how long the injury will keep his ace out of action. But the D-backs manager believed it was the right move to remove Greinke when he did.
"It's something that maybe he could miss a start, possibly not miss a start, possibly at the worst maybe 15 days on the DL, you never know," Hale said. "But if you go out and really yank it bad, you're talking about a month or two. We'll hope for best-case scenario."
Greinke will be re-evaluated on Wednesday before the D-backs decide the next course of action.
The D-backs invested a lot in Greinke this past offseason, signing the three-time All-Star and former Cy Young Award winner to a six-year, $206.5 million deal.
The injury comes at a frustrating time for the D-backs as Greinke was beginning to return to form after a rough start to the season. He had a superb June, posting a 1.63 ERA in six starts for the month.
"I felt I've been pitching pretty good for a while and felt really good today," Greinke said. "Hopefully it's nothing major, we'll find out more in the next couple days. Hopefully it's nothing much at all and I can continue pitching good."