GOODYEAR, Ariz. -- Patrick Corbin's final start before his assignment to open the regular season on the mound for the D-backs next week in Australia took an abrupt detour Saturday when he left his outing against the Indians in the seventh inning with forearm stiffness.
The left-hander was cruising right along into the seventh when, in the middle of an at-bat, he suddenly motioned for a mound visit from manager Kirk Gibson and pitching coach Mike Harkey, along with the D-backs' assistant trainer Ryan DiPanfilo. Now the starter for the D-backs' first game of the regular season is hanging in the balance.
Corbin left Goodyear Ballpark immediately after exiting the Cactus League game to be examined by D-backs medical personnel at Salt River Fields, and Gibson said after the game it was too early to tell exactly what is ailing Corbin, or how that might affect his availability in Australia.
"We'll look at it, and rest assured we'll be cautious with it," Gibson said.
Gibson described the injury as being on the inner part of the forearm, which may or may not be the extent of the trouble.
"We certainly hope it has nothing to do with the elbow, but we'll try and determine that tonight," Gibson said Saturday afternoon.
The condition came as a surprise to Gibson and catcher Miguel Montero, who had watched the 24-year-old left-hander work a strong start into the seventh. But after his 91st pitch of the day, he called DiPanfilo, and within moments, his outing was over, and his status was sent under a cloud of uncertainty.
Corbin, who went 14-8 with a 3.41 ERA in 32 starts in 2013, was slated to push toward 100 pitches Saturday, but he fell nine short of that when he came out of the game. The 2013 All-Star and D-backs Most Valuable Pitcher wound up allowing two runs (zero earned) on 10 hits while striking out seven in his fourth start of the exhibition season.
Although Corbin struggled through a 24-pitch second inning, there weren't any strong indications that anything was wrong with him until the seventh. He responded with a 1-2-3 third and wasn't scored upon the rest of the way while scattering 10 hits on the day.
"He kind of started off slow but settled down and started pitching pretty good, which is why it stinks what happened there at the end," Gibson said.
Montero said he thought at first that Corbin might have twisted his ankle or tweaked his groin when he called for the visit to the mound. He wasn't thinking it was Corbin's arm.
According to Montero, the only indication in retrospect that something might have been off is that Corbin's breaking ball wasn't working as well as it usually does, and perhaps that was an indication something was off.
"He couldn't really put them away with that breaking ball he normally throws," Montero said. "It was just kind of floating out there and backing up. That might be the reason why."
Up until the surprise conference on the mound in the seventh, Saturday's outing was looking like a routine tuneup for the pitcher who would throw the first pitch of the Major League season. But, suddenly, that storyline changed, and it might have changed drastically.
"He's the guy who's going to pitch the first game for us, and I don't know if he's going to or not," Montero said. "I don't know what the situation is, but obviously there's some concern. He's some weapon, you know?"
Gibson would not talk about what options the D-backs had to replace Corbin for the March 22 opener against the Dodgers because that hadn't been discussed internally, and he said the D-backs are taking a wait-and-see approach.
"We'll make a good decision," Gibson said.
John Schlegel is a national reporter for MLB.com. You can follow him on Twitter at @JohnSchlegelMLB. This story was not subject to the approval of Major League Baseball or its clubs.