For Philadelphia, it is clear that they are parting with McCoy largely to save money given that he has a nearly $12 million cap hit this upcoming season as well as to part with a player that clearly had some issues with head coach Chip Kelly, who now is making the personnel decisions for the team. McCoy is one of the top backs in the league right now but he did take some steps back this past season after an exceptional 2013 campaign. Darren Sproles is on the wrong side of 30 and has never been an every down back while Chris Polk did not show all that much last season, meaning the Eagles are going to have find a replacement for McCoy this offseason.
Not only are the Eagles taking a risk in parting with a back that has not hit his prime yet, they are also taking a risk on Alonso, who did not play last season after tearing his ACL before training camp last summer. That said, it is still a good move on Philadelphia's part. Alonso had himself a sensational rookie campaign in 2013 with Pro Football Focus saying that he had the fourth best coverage season for a linebacker since 2007, and he will team up with the talented Mychal Kendricks to give the Eagles a infusion of speed and athleticism to a linebacking corps that sorely needs it. His acquisition will also only help one of the worst pass defenses in the NFL. Of course, the key is for Alonso to stay healthy.
Now for Buffalo, it is an interesting move for new head coach Rex Ryan to part with such a talented defensive player because we know how much Ryan loves to focus on the defensive side of the football field. Buffalo's defense was still tremendous without Alonso this past season but one would have thought that Ryan would have loved to work with a player of his caliber and talent.
But I think that with this acquisition of McCoy, the Bills under Ryan are going to seriously focus on running the football. As noted already, McCoy did decline last season and struggled to pick up yards after contact but he was still the third leading rusher in the NFL this past season. He is going to a team with an offensive line that really struggled in the run game last season, and one that is still looking for an answer at the quarterback position. That said, new offensive coordinator Greg Roman is a big proponent of running the football and Ryan's teams in New York had run-dominant offenses, meaning that McCoy should get plenty of work. He already should stand as an upgrade over C.J. Spiller, who seems to be on his way out of town now.
All in all, while both teams are taking on some amount of risk with these moves, I think the Eagles may have come out on top in this regard. Any offense could use a playmaker with the skills that McCoy brings to the table but the innovative work Chip Kelly does with his offensive schemes mean they might be able to get away with what ultimately will be a downgrade at running back. But the ultimate key is for Alonso to stay healthy but if he fails to do so and if McCoy goes off for the Bills, then the opposite will be true.