The Denver Broncos have little depth at quarterback, so it must have been concerning to the team that the expected starter -- Mark Sanchez -- required surgery on the thumb of his non-throwing hand.

The Broncos said he underwent the procedure last week and is expected to miss the start of offseason training activities. Denver said Sanchez initially injured the thumb while working out at the team facility, suffering a torn ligament in his left thumb.

The injury leaves the Broncos with little experience under center for the start of OTAs. Little-used Trevor Siemian and first-round pick Paxton Lynch will split the snaps while Sanchez recovers.

More from FoxSports

The Broncos acquired Sanchez, who is 37-35 as a starter in his career, from the Eagles for a conditional seventh-round pick in March.