Everyone earns their spot. The 5th string RB at Alabama every year might be absolutely amazing, but it's guaranteed that he's going to have to wait his turn usually behind a few other amazing guys.
Sometimes you have to wait your turn and earn your spot. These schools aren't like BYU where sometimes we're barely 2 deep. He has one healthy, rookie season in the books.

Now he's fortunate enough, since his freshman year, to have 2 guys ahead of him gone to the NFL, and now Sanders is likely done. Other than that it's basically just Shipley so it's definitely his shot if he's healthy and if he stays out of trouble which is hard for him. Honestly, he may not even last the season with Strong as the coach. Strong doesn't tolerate crap and Johnson is a trouble maker. Some think he's not even going to last on the team because he was in trouble at the end of last year. Which is why he needs a ton of time on the field to help keep him focused. If he's healthy and smart he could end up with a huge year.

Honestly though, some are wondering if he's going to get another chance. One screw up and I bet he's off the team.