College football, on the line especially, is all about measurables, size and speed, footwork, and projecting how a player will fill out. They look at a Tate Nichols, who played tight end, and can see a good lineman's body. They'll look at your kid and project where his body will be in two years. If they like what they see, no worries.
Other option, if no offers that are acceptable, try a year of prep school.