Eaton, 24, was slated to take over as Arizona's leadoff man following an offseason lineup rebuild. He went 23 for 59 (.390) with two homers and three steals in spring training after an impressive 22-game cameo last September (111 OPS+). Baseball America ranked Eaton as the 73rd-best prospect in the game a few weeks ago.
With Cody Ross (calf) a question mark for opening day, the Diamondbacks are suddenly thin in the outfield. Gerardo Parra figures to step right in and assume everyday center field duties, meaning prospect A.J. Pollock or speedster Tony Campana could make the team as Eaton's injury replacement. Both could make the club if Ross misses any time.