GOODYEAR, Ariz. — The fastball topped out at 97 mph. The hitters couldn’t catch up with it. By all appearances, left-hander Aroldis Chapman was back in form after a one-week layoff because of back spasms.

The Cuban defector pitched one inning of a minor league game for the Cincinnati Reds on Sunday, having little trouble with up-and-coming Milwaukee Brewers. He struck out the first two batters he faced — one of them on a nasty slider — and gave up a single up the middle before getting the final out on a routine grounder.

“I felt like before,” Chapman said, with a trainer acting as translator. “I feel really good.”

The 22-year-old pitcher was in the running for the fifth starter’s spot before spasms in his lower back forced him to leave a game last Monday. He didn’t throw for two days, giving the back time to recuperate.

While the rest of the team played the Dodgers at a stadium down the road on Sunday, Chapman went to one of the back practice fields behind the Reds’ complex, testing his back in a very low-key setting against minor league hitters.

Chapman’s fastball hit 100 mph on radar guns during earlier appearances this spring, when he threw a little harder each inning he stayed on the mound. He threw 19 pitches on Sunday, 12 of them strikes. A couple of them hit 97 mph on a radar gun set up on a white table behind the backstop.

“I could have thrown more than one inning,” Chapman said. “There were only two days I stopped throwing.”

What happens next is unclear.

The Reds signed Chapman to a six-year, $30.25 million deal in January, planning to go slow with a player who was going through culture shock after defecting. They held open the possibility that he could win the final spot in the rotation, but there was a crowded field of youngsters and veterans competing for the job.

With a week left before Opening Day, the competition is down to three: left-hander Travis Wood, right-hander Mike Leake and Chapman. None of them has pitched in the majors.

The Reds have three days off in April, so the fifth starter won’t necessarily get much of a chance to pitch. The Reds will have to weigh whether it’s best for Chapman to pitch regularly in the minors, giving him a chance to refine his delivery before bringing him to the majors for the first time.