"I thought I jammed the thumb on the dive, but the X-ray seems to show a chipped bone in the thumb," Hairston said after the game.

Hairston will have an MRI Thursday morning as the rest of the Padres take a day off.

"It feels terrible, so I don't think the MRI is going to be good news," he said.

Since left fielder Chase Headley was called up in June, Hairston has shared center field with Jody Gerut, playing mostly against left-handed starters. Hairston hit eight of his 17 homers in July but was only 9-for-43 (.209) with three doubles and no RBIs this month as the streaking Gerut saw more playing time.

Hairston is batting .248 overall.

PADRES 5, DIAMONDBACKS 4: The Padres rallied from a 4-0 deficit against Randy Johnson on Wednesday to complete a three-game sweep the NL West-leading Diamondbacks at Petco Park. The Padres, who rank last in the league both sacrifice bunts and steals, used one of each in the eighth, scoring two "small-ball" runs on three singles. C Nick Hundley hit a two-run homer for the Padres, while OF Jody Gerut was 3-for-4 with a triple and his second game-winning hit against the Diamondbacks, a tiebreaking single, in three games.