There is a chance McCoy's career in Buffalo ends in similarly disappointing fashion.
A succession of roster moves this offseason has given the Bills increased flexibility to transition away from McCoy as early as this summer. Buffalo's signing of three veteran free-agent running backs (Frank Gore, T.J. Yeldon and Senorise Perry) and drafting of Florida Atlantic's Devin Singletary in the third round last week does not mean McCoy will be gone, but his roster spot seems far from guaranteed given the climate at the position.
McCoy has seen sharp statistical decline the past two seasons, and he approaches his 31st birthday in July. His average yards per carry has dropped from a career-high 5.4 in 2016 to 3.2 last season, his worst as a pro.
Such a downward trend is typical for rushers at his age. Among all players with at least 75 rushing attempts per season over at least four years since 2001, their rushing average has declined from 4.29 yards per carry at age 28 to 4.09 at age 30 and 3.82 by age 32.
One of the exceptions has been Gore, whose average dipped below 4.0 yards per carry from his age-32 season (2014) through his age-34 season (2016), only to rebound to 4.6 last season at 35 for the Dolphins.
Now Gore has a chance to unseat McCoy as the top back in Buffalo. Yet, similar to how McCoy could recover and re-establish himself as the engine that drove the Bills' offense in 2015 and 2016, Gore could finally show signs of age and fail to make an impact.
Add in two younger wild cards -- Yeldon and Singletary -- and the scenarios of how the Bills could distribute snaps in their backfield this season begin to multiply.
In the short term, general manager Brandon Beane and coach Sean McDermott seem content to let the competition play out. Both stood by McCoy at the end of last season, reiterating he was part of the team's plans in 2019. Instead, they focused their attention on improving the blocking in front of McCoy, firing offensive line coach Juan Castillo and signing a staggering six free-agent linemen.
Even Friday, after the Bills drafted Singletary, Beane said there was "no question" McCoy remained the starter.
Given team decision-makers are typically averse to making such declarations this far in advance of the season, and that general managers are usually careful of stepping on coaches' toes about naming starters, it would be reasonable to deduce some posturing from Beane. If the Bills desire to trade McCoy, they need other teams to believe he will not be available on the open market as a free agent. It would be smart for Beane to be firm on McCoy being the starter, not a candidate to be released.
In reality, the Bills added four running backs this offseason with a realistic shot of making the 53-man roster: Gore, Yeldon, Singletary and Perry, who played an important role on special teams for the Dolphins and would be the top candidate to fill a similar role as the third or fourth running back on Buffalo's 53-man roster.
The numbers continue to suggest McCoy's job is in trouble. Even if the Bills cannot or do not trade McCoy, his release anytime before Week 1 would save the team $6.175 million against its 2019 salary cap -- free space that can be carried into 2020. Savings also can exist by cutting Gore ($1.25 million) and Yeldon ($750,000), but the financial upside to moving on from McCoy sticks out.
Ultimately, the Bills do not have to make any decisions in May about their backfield. They could use training camp and the preseason to gauge where McCoy and Gore stand in their careers, and how Yeldon and Singletary might fit into their plans. Injuries could affect the outlook, and injuries elsewhere could ignite the trade market for McCoy.