"Dallas flew back to Houston to get further evaluated," Hinch said. "He played catch in Texas the last day and didn't feel great, so he flew back to see our doctors, had some tests. He's been diagnosed with shoulder inflammation, which we knew.
"It just hasn't resolved, and he hasn't been able to play catch, so we're going to shut him down for the time being. He won't make tomorrow's start. He won't make his start this weekend, either. We'll get back to Houston and evaluate what's next for him, but he went back to Houston."
Keuchel had been slated to start Friday at Texas, but Hinch announced Wednesday that Keuchel's next start would be pushed back a day or two due to soreness.
On Monday, he said he didn't know if Keuchel would pitch again this season.
"We'll have to get back and see how all these tests come back and how he continues to feel," he said. "We tried to give him some gaps in time and give him some rest period, but that hasn't solved it. He's going to go see the doctors he needs to see, and until he's pain free, he's not throwing. Where we are in the calendar is going to bring the obvious questions, but we just don't know right now. "
Hinch said Brad Peacock will start in Keuchel's place Tuesday.
Keuchel, the reigning American League Cy Young Award winner, had a rebound month in August, going 3-1 with a 3.10 ERA, but he cited lingering soreness as a reason for pushing back his start.
After a slow start to the season, the Astros have jumped back into the wild-card chase in the American League, trailing the second spot by only 2 1/2 games.
Hinch said all players feel some soreness this time of year and that Keuchel had been especially good at battling through it, but not this time.
"I think it's just since his last start," Hinch said. "It was just the recovery from his last start. It wasn't anything that stood out. It was just that the next day he woke up and felt the soreness that he continues to talk about."
The Associated Press contributed to this report.