ANAHEIM -- The Reds were banking on the healthy returns of Hunter Greene and Nick Lodolo for a late-season playoff push, but a development has potentially derailed that hope. 

Lodolo, who has been out since mid-May with a stress reaction in his left tibia, was dealt a setback during his most recent rehab start for Triple-A Louisville on Sunday. 

"He dealt with that all that time and then he felt something in there again and it showed something on the MRI," Reds manager David Bell said on Tuesday. 

Lodolo began his start against Iowa with two scoreless innings before he started struggling in the third. He allowed two singles and three walks, leading to a pair of runs, and was lifted from the game. 

“I think it kind of happened around that third inning of the game he was pitching in," Bell said. "He’s getting a second opinion right now but the MRI showed a stress reaction, so it’s just a reoccurrence. Obviously, it’s concerning news, but I don’t have anything beyond that.”

Lodolo was slated to pitch five innings in one more rehab start before a potential activation from the injured list on Aug. 30. That now appears highly unlikely. 

In seven starts this season for the Reds, the 25-year-old left-hander went 2-1 with a 6.29 ERA. He was 2-0 with a 2.12 ERA in his first three starts, and 0-1 with a 10.38 ERA over his last four. 

Lodolo's setback came after Sunday's disastrous return for Greene, who allowed nine runs (eight earned) and 10 hits over three-plus innings vs. the Blue Jays. He tied a career high and club record by surrendering five home runs in a 10-3 loss.

Cincinnati entered Tuesday with the 28th-ranked rotation ERA (5.38). The club has limited options to fill its starting five for the final month of the season should Lodolo be unable to return.

Ben Lively, on a rehab assignment with Louisville, has been on the IL with a right pectoral strain -- his second occurrence of the injury -- since Aug. 2. He is slated to throw 85 pitches in one more rehab start and could be available for the Reds in the first week of September. 

Brett Kennedy pitched five scoreless innings in his previous start, vs. Toronto on Aug. 18. Rookie Lyon Richardson, who is on the taxi squad, might not be as much a possibility, as he is on an innings limit.

The Reds entered Tuesday third in the National League Central, four games behind the Brewers, and one game back for the third spot in the NL Wild Card race.