The sky began to fall in Denver on Thursday after the report that Pro Bowl left tackle Ryan Clady is likely out for the season with a torn ACL. This leaves right guard Louis Vasquez as the only remaining starter from last year's offensive line. This many changes up front can doom your season, especially when its fate hinges on protecting 39- year-old Peyton Manning. We already had Denver's offensive line pegged as the team's biggest weakness, and it just got weaker.

In his 18th season, Manning has arguably never had an offensive line this unaccomplished. The Broncos will potentially start a second-round rookie at left tackle (Ty Sambrailo). Left guard Shelley Smith, signed in March, has 11 career starts. Center Gino Gradkowski, acquired from Baltimore in April, has 16 career starts and will face competition from Max Garcia, a fourth-round rookie. On Thursday, suddenly desperate for depth, Denver signed right tackle Ryan Harris, who started 15 games for Kansas City last year.

There is also the issue of new coach Gary Kubiak meshing his offensive scheme with Manning's. The change is likely to mean more snaps from under center and more play-action. Clearly, the Broncos have a ton of work ahead of them to make this offense still run smoothly come September.

Then again, as long as Manning is the quarterback, does it really matter who starts along the offensive line?