The only thing thinner than the air at the Broncos' mile-high training camp is their safety depth.  

The hamstring and knee injuries that S Quinton Carter suffered during the second day of training camp July 27 necessitated arthroscopic surgery that will keep him out at least two weeks, The Denver Post first reported Friday.

Carter hasn't practiced since suffering the injury, which came when he dove after a deep pass meant for Eric Decker. Carter lost his footing on the artificial surface at the South Suburban Sports Dome, a public facility the Broncos use when inclement weather keeps them from practicing outside.

Carter and fellow second-year S Rahim Moore had been expected to challenge for playing time alongside veteran S Mike Adams, but Carter's absence gave Moore the work by default. Carter replaced an ineffective Moore in the starting lineup six games into last season and kept the spot for the rest of the year.

Denver's complement of reserve safeties consists of Rafael Bush, David Bruton, Anthony Perkins and Duke Ihenacho, who have combined for just six career starts in the NFL -- all by Bruton.

To alleviate the lack of experience, the Broncos could turn to former Jets and Ravens S Jim Leonhard.  Jason LaCanfora of tweeted that the Broncos will work out Leonhard on Saturday.

For up-to-the-minute Broncos updates, follow Andrew Mason on Twitter at @CBSSportsNFLDEN and @MaxBroncos.