Zito left the clubhouse at Chase Field on crutches after the game, which extended San Francisco's current winning streak to four. His personal streak of never having missed a regular-season start because of injury may be in jeopardy. Zito's next slated to start against the Braves in San Francisco on Friday.
"You never know, incredible things can happen," Zito said. "We'll see what the MRI shows tomorrow and we'll take it day by day."
As Arizona rallied in the bottom of the inning from a 2-0 deficit, Zito dove forward to catch a pop bunt by D-backs pitcher Joe Saunders in front of the mound. Zito made the catch, but as he readied himself for the next hitter, Giants athletic trainer Dave Groeschner came to the mound at the urging of catcher Buster Posey.
After some discussion, Zito took a warmup pitch and then walked off the field accompanied by Groeschner and manager Bruce Bochy. Zito had already allowed a pair of doubles in the inning, the second of which, struck by D-backs catcher Miguel Montero, drove in two runs.
Zito said he felt his foot land strangely on the turf as he tried to push off to make the play, although he didn't twist it.
"I was just pushing off to get the bunt," Zito said. "My foot went at a weird angle. I threw the pitch, saw the ball come off the bat and went to go get it. It's really odd. I put my weight all on one foot just to jump."
Zito is 0-1 with a 6.23 ERA in three starts this season. He hasn't won since Sept. 19 in San Francisco over the Brewers and was left off last year's playoff roster for all three rounds as the Giants won the World Series for the first time since 1954.
Zito is earning $18.5 million this year in the fourth year of a seven-year contract that guarantees him $126 million. Since joining the Giants for the 2007 season, Zito is 40-58 with a 4.47 ERA.
He was already in a car accident in Los Angeles on the eve of the March 31 season opener at Dodger Stadium. Though he sustained a neck injury in the collision that totaled his rental car, Zito made his first start as scheduled on April 3 during that four-game series, saving the streak that may have ended Saturday at 356 starts. He threw six innings that day in a 7-5 loss.
"I was able recover from that accident and it was huge," Zito said. "So maybe things we'll work out. We'll just see."