After shortstop Addison Russell suffered a setback in his recovery from a foot injury, it appears that the Chicago Cubs may be preparing for worst case scenarios.

In an interview before the Cubs’ game Thursday against the Pittsburgh Pirates, manager Joe Maddon said that the team is concerned that Russell could be out for the remainder of the season.

“There’s no assumption,” he said. “He could be out the rest of the year. He could be back. I don’t know.”

Russell has been out since Aug. 3 with plantar fasciitis in his foot. He began a rehab assignment earlier this month, but he was shut down after experiencing a setback with the injury. The Cubs said that they expected him to be out for another three weeks after an MRI revealed that he had re-aggravated the injury, but it sounds like the shortstop could be out longer than that.

In Russell’s absence, Javier Baez has been thriving at shortstop, hitting eight home runs and 28 RBI since the beginning of August.