"It's progressed, but I didn't want it to get worse just to come here," Reds head trainer Paul Lessard said on Friday. "He's tried to go off a mound, but it's still tender. That's why we didn't want to continue to keep going off a mound."
Cingrani hasn't pitched since exiting his last start Sept. 10 vs. the Cubs with back spasms. He also missed two starts on the disabled list in August because of a lower back strain.
The rehab program will continue in Cincinnati.
"We didn't want him to take a puddle jumper [flight] out here just for him to hang out here and be here," Lessard said. "I'd rather him stay there and keep working on it."
In his rookie season, Cingrani is 7-4 with a 2.92 ERA in 23 games, including 18 starts where he filled in for the injured Johnny Cueto. With Cueto just back from the DL after missing 2 1/2 months with a strained right lat, it could be tough for the Reds to carry two pitchers with iffy injury situations. Cueto looked good during his start of five scoreless innings vs. the Astros on Monday.
Cingrani's status will be evaluated next week, when the Reds are back home for the final week of the regular season.
"We would like to have him, but life goes on," Reds manager Dusty Baker said.