• Astros Spring Training: Tickets | Schedule | Info
McCullers threw an intense live batting practice session earlier this week against Carlos Correa, Carlos Gomez and George Springer.
"That was a pretty heavy day for him, and his throwing hasn't bounced back as well," Hinch said. "Most of it is normal Spring Training stuff, but we're going to have him see the doctors who are here for the Minor League physicals and take that step."
• Hinch's updates from Spring Training
The Astros have targeted this weekend all along for McCullers to get on the mound. He threw 157 2/3 combined innings last year between the Minor Leagues and the Astros after throwing only 97 the previous year. The Astros planned to bring him along more slowly than the rest of the pitchers to monitor his workload.
• Reliever Ken Giles had his best outing yet of the spring in Friday's 10-4 win over the Tigers, allowing only a solo homer in one inning of work. He struck out one batter. Hinch said he wanted Giles to try to throw more sliders so his fastball wouldn't get ambushed.
"He's got a good fastball, and he's got elite stuff," Hinch said. "You still have to execute, and you still have to make pitches, and he did that today. … Valuable day today for Giles to see his slider implemented a little bit more, and then the feel for it was excellent. His strike-throwing was a step forward."
Giles, who had allowed four hits and three runs in his first two outings, said the things he's been working on are starting to pay off in games. He was sitting at 85-86 mph with his slider and 97 mph with his fastball.
"A lot better than the last two outings," he said. "Just the little things I was working on in the side are starting to show now, and I'm finally getting my timing down a little bit. I threw more sliders today, and they were really sharp today. I was very happy with it."
Brian McTaggart is a reporter for MLB.com and writes an MLBlog, Tag's Lines. Follow @brianmctaggart on Twitter and listen to his podcast. This story was not subject to the approval of Major League Baseball or its clubs.