Doug Marrone has said that he does not know whether EJ Manuel will be available for the Buffalo Bills' final game of the 2013 NFL season.
The rookie quarterback missed last week's 19-0 win over the Miami Dolphins with a sprained knee.
The head coach told reporters: "Both quarterbacks participated in practice. Both quarterbacks participated in team. EJ looked improved today and we're still in the process of making a decision on how we're going to move forward.
"I was still a little backed up as far as getting EJ out there and working on that type of field where the conditions are a little more slippery, along with some other guys that have some nicks and bumps.
"I just want to see the confidence to be able to do the things that we're asking him to do to win the game. That's where the responsibility gets a little tough where you have to make tough decisions."
The Bills face the New England Patriots on Sunday.