"I guess you can call it back spasms or a stiff lower back," Yankees manager Joe Girardi said after New York's 3-2 win over the Red Sox. "He had an MRI and the MRI came back clean, so he's more day to day."
Roberts, 36, missed 445 games over his last four seasons with the Orioles due to a variety of injuries. He is batting .129 (4-for-31) with an RBI in 11 games for the Yankees in 2014, his first season in New York.
With Roberts out of the lineup, the Yankees started rookie Yangervis Solarte at second base on Sunday, Solarte's second start of the season at the position. Rookie Dean Anna also has started twice at second base.
Girardi said that he expects the Yankees will have to make some roster moves before Tuesday's game against the Cubs. One will likely be to place catcher Francisco Cervelli on the disabled list with a right hamstring injury, but Girardi suggested that the Yankees would consider adding infield depth because of Roberts' uncertain situation.
"I would anticipate we'll probably make a couple of moves," Girardi said. "I think we're going to have to, maybe not knowing what Brian's status is on Tuesday. We don't expect it to be real long, but we might have to make a couple moves."