PHOENIX - A's pitcher Brett Anderson suffered a strained right trapezius muscle after just eight pitches Sunday when he tried to cover third base on an error and collided awkwardly with Arizona Diamondbacks baserunner Adam Eaton.

The 25-year-old left-hander said he came out of the game for precautionary reasons and didn't think the injury was serious.

"I feel all right," said Anderson, who said the stimulus treatment he was receiving considerably relieved the pain after about 20 minutes. "It was a kind of freak play at third that you don't really expect to happen, but it's part of the deal sometimes. I don't think it's anything major — it's a neck strain/spasm, if you will. They didn't really give me a timetable or what my process is, but it's nothing to be too concerned about."

After Eaton had opened the game with a leadoff single, former A's shortstop Cliff Pennington hit a chopper to third baseman Josh Donaldson, who misplayed the ball for an error. As Donaldson went to retrieve the ball to his left, Eaton rounded second base and broke for unoccupied third. Anderson belatedly sprinted over to cover but Donaldson's relay's was behind him and he but slid awkwardly into the base and Eaton.

"It was pure athleticism at its finest at third base," the pitcher said.

Anderson, who was making his second spring training start, walked back to the mound under his own power but did not even attempt a warmup pitch before being removed from the game by A's manager Bob Melvin and the Oakland training staff. Anderson left the field rubbing the back near the base of his neck, where the trapezius muscle is located.

"You want to pitch and get your work in, but you don't want to overcompensate and hurt something else more than your neck, whether it be an arm or your legs by changing your mechanics," he said. I'm not too worried about it. I expect it to be stiff for a day or two, we'll see, but I don't expect anything major."

Anderson was asked if he got anything out of his eight pitches.

"I threw a good changeup," he said. "It was a moral victory. (Pennington) fouled one off and I was giving him a hard time. I told him that was probably one of the better ones I've thrown and he had a little laugh about it. It is kind of funny he's the guy who hit the ball where I got hurt."