Antonelli hit .378 with one home run and eight RBIs in 37 at-bats with the Padres during Spring Training. Antonelli, the Padres' No. 1 Draft pick (17th overall) in 2006, is set to be reevaluated on Wednesday.
Randy Smith, the Padres director of player development, said Antonelli has been wearing a splint to "quiet down" the injury.
Smith said that there's no fracture to the hook of the hamate bone, an injury similar to the one Padres shortstop Everth Cabrera had last season.
That has Smith encouraged that Antonelli will be able to begin his season with Triple-A Portland in a few weeks.
Antonelli will be in Portland for the third consecutive season, though he feels he is much better equipped to have success there after reworking his swing last fall with the help of Tony Muser, the Padres roving hitting instructor.
Also, left-handed pitcher Cory Luebke will eventually begin the season with Double-A San Antonio, though he'll start the season the disabled list after straining his oblique in Spring Training.
Smith said that it could be early May before Luebke returns to action. Luebke was a combined 11-4 with a 2.78 ERA in 23 starts between Class A Lake Elsinore and San Antonio.