This is key. In today's NFL, you are either special or you are replaced after your rookie contract, left to sign in a RBBC. People were at one point pretty excited about owning guys like Hyde, Gio, Doug Martin, Latavius Murray, Alfred Morris, etc. in their first 2-3 years in the league. But it seems like 9 out of 10 marginal talents just get left for dead in free agency. I mean CJA was coming off a 1000 yard season and had to settle for a back-up job last year, showed he could still play on the Rams, and then still could only get a backup job the next cycle. Tevin Coleman owners all thought he was going to get a starting job in free agency, then RBBC. Some guys don't even make it to free agency. Jeremy Hill, Jordan Howard, and Eddie Lacy were fantasy scrubs after just 3 years.
But when I say 9 out of 10, that means there are exceptions. Very few non-owners ever thought Lamar Miller was special, but he landed a starting job. I'm struggling to think of another middling talent that was signed to be a starter. McKinnon almost was if not for injury, but he isn't a great example since he didn't start much during his rookie contract.