"Once we get him out on a field, we'll see how many at-bats we can get him," Melvin said. "To an extent, a lot of it has to do with how he feels, first physically, and then at the plate. We want to make sure that we feel comfortable progressing him into a certain amount of games, a certain amount of innings.
"He feels great. He wants to get out there, but there's a progression that we need to see."
Despite Gentry's setback, Melvin still seemed confident he would be good to go by Opening Day, saying the club was being "overly cautious" in an effort to avoid a relapse.
In the meantime, Sam Fuld and Michael Taylor -- next in line behind Gentry on Oakland's outfield depth chart -- have been seeing plenty of playing time. Taylor has five hits in his last seven at-bats. Fuld hit his first homer of the spring on Thursday and is sporting a .333 average through seven games.
"We knew that he was this type of player, and he was a guy we were happy about getting when we did," Melvin said Thursday of Fuld. "When you have him as depth, with the Gentry situation right now, you're in a pretty good situation.
"He's a big league player. We can only have 25 guys, and we'll see what 25 guys we start with."
Jane Lee is a reporter for MLB.com. Read her blog, Major Lee-ague, and follow her on Twitter @JaneMLB. This story was not subject to the approval of Major League Baseball or its clubs.