Visiting NFL Network's NFL AM on Tuesday, the running back reiterated that the ball is in the Bills' court as far as a return.
"He learned that you can't be buddy buddy with everybody," Spiller said. "You're the face of the franchise, you're the quarterback so you have to demand everything. ... I think early on he didn't really didn't understand how to step on guys' toes. Once Kyle took over, he saw what Kyle did and it helped him.
"He's a tremendous worker. The guy comes to work every day, prepares unbelievably. He's in there first, last one to leave, so he has all that stuff. It was just that buddy buddy. You know how it is, you come in with some guys in your draft and you don't really want to step on their toes. As I told him 'You're the quarterback you have to (step on guys' toes)' and I think he learned that."
The ability to lead a team is one aspect in which Manuel needed to improve over the past year. The other -- and more important -- is his ability to read defenses and not spike passes four feet in front of receivers.
As far as Spiller is concerned, the year sitting and watching only helped Manuel grow.
"He has everything he needs to be a successful quarterback and I think if Buffalo gives him a chance, he can definitely lead that organization," he said.
The organization, lacking for quarterback options outside of Manuel after being spurned by Josh McCown, is praying with gripped hands that Spiller is right.