KANSAS CITY, Mo. -- The good news for the legions of Tim Lincecum fans is the pitcher returned to the mound for the San Francisco Giants on Wednesday in the World Series and threw 1 2/3 scoreless innings of relief.
The bad news is he left the game with tightness in his lower back and is day to day. Lincecum was sent for an MRI on Thursday.
"I felt good. It was nice to get out there and compete a little bit, but outside of all that, what I'm really thinking about now is hurting myself," Lincecum said after the Giants' 7-2 loss to the Royals. "It's all right now. We're just going to treat it and see how it feels tomorrow. But right now, it just feels pretty stiff."
Trainer Dave Groeschner said in a text message Thursday that Lincecum "is doing OK'' and will be checked out further.
Brought into the game in the seventh inning with San Francisco trailing by five runs, Lincecum retired the first five batters he faced, striking out two of them. Then he suddenly left the game.
"The pitch before the last one, I felt something tighten up in my lower back," Lincecum said, adding that it was more stiffness than pain. "I just decided not to go any further."
Lincecum has pitched very little since the Giants dropped him from the rotation in late August. He pitched in only six games and a total of 10 1/3 innings after the move, and he had not pitched this postseason. His last appearance was the final day of the regular season.
Lincecum said he didn't think the layoff contributed to the injury.
"I've been on the mound a few times in bullpen sessions, and I've been trying to go full-bore in those, so I don't think it's any issue that has to do with that," he said.
Manager Bruce Bochy, however, was not so sure.
"That's hard to answer -- I don't know," Bochy said. "But I will say he took an extended pen a couple days ago and really threw a lot of pitches to get himself ready. So it might have, I don't know. But I will say his first inning he threw the ball great. He was throwing the ball great up until that point, so it might be true."
Lincecum also asserted the layoff didn't affect the way he pitched.
"You get out there in the game-time atmosphere, and you don't worry about how long it's been," he said. "You just go out there and compete. Your body taps into what it's comfortable with, and today that's what it was."
Bochy said he was impressed with the way Lincecum pitched before the injury and that he will use him again if healthy -- which he might need to do, given the way the San Francisco bullpen collapsed before Lincecum came into the game Wednesday.
"We're going to need help in the sixth, seventh inning," Bochy said. "I like the way he threw the ball today. It's been awhile since he pitched. But I thought overall he looked good for the long layoff. So he can be in the mix."
Lincecum was a key part of the Giants' rise from losing seasons to multiple World Series. He won two Cy Young Awards and was instrumental as a starter in the 2010 postseason and as a reliever in the 2012 postseason. Despite throwing two no-hitters, he struggled and was inconsistent the past couple of seasons and had a 4.64 ERA when the Giants pulled him from the rotation. He won two games in relief after that move.
"I'm still on the roster," he said. "I still have an opportunity to get out there, and I just have to wait for that chance and be ready for it."
On Tuesday, he missed pregame introductions before the opener, failing to line up with his teammates on the third-base side of the field because he was in the clubhouse vomiting.
"My trainer, Dave Groeschner, he said [Lincecum] got sick about a half-hour before the game and he was throwing up," Bochy said. "He rebounded very well. He was OK to pitch."
Bochy wasn't sure whether the issue was caused by food.
"I don't know if he knows," Bochy said. "He was down in the bullpen, I think, the second inning."
Despite the loss, the Giants felt good about the split in Kansas City.
"Taking one of two games here is always a good thing," Lincecum said, "especially against these guys in this kind of atmosphere."
Information from The Associated Press was used in this report.