Oakland Raiders OLT Khalif Barnes was injured during Tuesday morning's training camp practice. Barnes, who signed a one-year, $1.2 million deal with Oakland in March, suffered a hairline fracture to his left ankle, a league source told Scout.com. Barnes is expected to miss four to six weeks, which puts him out until at least the beginning of the regular season. Third-year OT Mario Henderson is expected to fill in at left tackle. Source: scout.com
Raiders LT Khalif Barnes Out 4-6 Weeks Raiders LT Khalif Barnes is out 6-to-8 weeks after Tuesday's injury, Raiders coach Tom Cable said. He expects the four-year starter to be back early in the regular season to provide depth. This also gives job security to right tackle Cornell Green, now that Barnes is no longer an option to flop to the other side. Source: SFGate.com
Mario Henderson showed flashes of being a nasty run blocker when he got playing time last year so this might not be horrible
I will say this again, OUCH! Who knows how long the lingering effect this could have, because I know that injuries to the ankle don't just heal up, it can feel great for a few days then a slightly awkward landing causes pain for days.