The month-long audition for the Yankees’ left field job is officially underway.

One day after the Bombers lost Curtis Granderson to a fractured right forearm that will cost him 10 weeks, Joe Girardi began the process of finding his replacement.

Minor-leaguer Melky Mesa started in left field against the Orioles Monday at Ed Smith Stadium, while Juan Rivera got the call in right field. Matt Diaz, another contender for the job, served as the designated hitter.

“I think one of the reasons they brought guys like me and Juan into camp was to provide depth, because you never know what can happen,” Diaz said. “My job here is to provide solid depth, so maybe that gives me a chance to show them that I’m capable of doing that.”

Two more minor-leaguers – Zoilo Almonte and Ronnier Mustelier – also made the trip for the Yankees’ 5-1 loss, as Girardi and his coaching staff plan to explore all internal options while general manager Brian Cashman looks at any potential fits outside the organization.

“I think you just have to look at the guys that you have within,” Girardi said. “Try to get them as much playing time as you can and try to decide what you’re going to do.”