SAN DIEGO -- Kirk Nieuwehuis suffered a torn plantar fascia in his right foot running up the first-base line in his first at-bat for Triple-A Buffalo on Friday, GM Sandy Alderson said.

Nieuwenhuis had been demoted last weekend to clear the roster spot for Mike Baxter's return from the DL. He was playing his fourth game for the Bisons on Friday.

Alderson said it was unclear whether Nieuwenhuis had suffered a full or partial tear. A full tear may be preferable, whereas surgery may be required for a partial tear.

"In some cases a complete tear is better than a partial tear," Alderson said. "It really will depend on the examination and how he responds as to whether surgery will be necessary. Surgery is often not necessary in these cases."

Also in Friday's game, Wally Backman was ejected after going toe-to-toe in an argument with Syracuse's manager. Both were ejected.