Diamondbacks left-hander Madison Bumgarner has been sent back to Arizona to be evaluated by the club's medical team after citing arm fatigue following his start against the Los Angeles Dodgers, manager Torey Lovullo said Sunday.

Bumgarner (0-1, 11.25 ERA) allowed five runs on four hits with four walks and two strikeouts in four innings of a 10-1 loss Saturday. He surrendered a grand slam to Trayce Thompson as part of a five-run first inning.

"My mechanics were fine. It was just one of those days you have during the year, and mine just happened to be the first one," Bumgarner said Saturday. "It wasn't like I went out there and threw the ball really well, but I was just one pitch away in the first of it being a completely different game. After that, it wasn't bad."

Lovullo said Bumgarner, 33, feels "very strongly" that he won't miss a start.

A four-time All-Star, Bumgarner is 134-122 with a 3.44 ERA in 358 career games (352 starts) with the San Francisco Giants and Diamondbacks.