HOUSTON -- D-backs outfielder Yasmany Tomas suffered a setback in his rehab from a strained right groin, and he will visit a specialist in Philadelphia on Monday to be further examined.
Tomas, who has been on the disabled list since June 3, had been running the bases and showing improvement as recently as earlier this week.
"If you've watched him run, the gait is good but there's a little discomfort that he's showing, and there might be a little limp every now and then, especially when he's slowing down," D-backs manager Torey Lovullo said. "He just wants to get to the bottom of it. We want to get to the bottom of it and find out what's wrong. The specialist will be able to determine exactly what's happening in that area."
Lovullo said it was too soon to determine whether Tomas would need surgery.
No Sunday starter announcement yet
One day after indicating that left-hander Anthony Banda would start Sunday against the Twins, the D-backs optioned him back to Triple-A Reno to make room for outfielder David Peralta's return from paternity leave.
Banda was 1-3 with a 7.32 ERA in four starts this year for the D-backs.
"We just felt like it was the best situation for him to go down and continue to work on a couple of things," Lovullo said. "Stuff-wise, it's close, but he needs to fine-tune some things and be able to make adjustments comfortably and not let innings get away from him. Continue to work on that mound presence and body language, and going out there with the stuff that he believes in and attacking hitters with every single pitch. He's still young and developing."
The D-backs have not announced who will take Banda's place Sunday. The candidates, according to Lovullo, are Reno pitchers Braden Shipley and Matt Koch, along with left-handed reliever T.J. McFarland.
Whoever it is will likely need to make just one start, as lefty Robbie Ray appears to be close to returning.
Ray, who suffered a concussion when he was struck in the head by a line drive June 30, is scheduled to make his first rehab start Thursday night for Class A Visalia. Banda had been filling Ray's spot in the rotation, and it's possible Ray could return as early as next Tuesday.
"We have some candidates that we're walking through," Lovullo said. "We still haven't made that final decision. Sunday is TBA. We want to get to it as soon as possible so we can let everyone prepare for what they're going to do."