Scottsdale, AZ (SportsNetwork.com) - Diamondbacks catcher Oscar Hernandez is expected to miss 4-6 weeks after breaking the hamate bone in his left hand.

Hernandez initially felt soreness in his hand on Monday, but felt a sharp pain after fouling a pitch off on Tuesday.

He will undergo surgery to remove the bone on Thursday.

Because he was selected from the Tampa Bay Rays with the first overall pick of the Rule 5 draft, Hernandez has to remain on the major league roster all season or be offered back to Tampa Bay. However, he can be placed on the disabled list and go on a rehab assignment with the Diamondbacks.

Hernandez, 21, played last season with Class A Bowling Green of the Midwest League, posting a .249 batting average and .301 on-base percentage and throwing out 41 percent of attempted base-stealers.