Two people familiar with the deal told the Associated Press on Tuesday that the
The deal has been agreed to, but can't be completed until the 2015 league season begins on Tuesday.
McCoy had an inconsistent season last year after leading the
He enjoyed his best season in 2013, scoring nine touchdowns rushing, adding 539 yards receiving and one touchdown.
One reason for McCoy's drop in production last season was a banged-up offensive line in which all five projected starters never played one game together.
McCoy's move to the Bills leaves
Buffalo's 2010 first-round draft pick told the NFL Network the Bills informed him of the trade, and told him "they were going in that direction, pretty much giving me a 'Thank you for your service."'
Alonso will be reunited with Chip Kelly, who coached the linebacker at