The Patriots have started the season 9-0 to establish a four-game lead with just seven weeks of the regular season to go, and victory over the 5-4 Bills would virtually secure the division title.
Ryan admitted that his team are only competing for a wildcard spot behind their opponents, but insisted that his side will be eager to step up their bid for a playoff spot by inflicting a first defeat on the 2014 Super Bowl champions.
"Right now we are second in the division," he told reporters. "We are going to do whatever we can. Does that give us the opportunity to win the division? No.
"[The Patriots] are going to win the division. I do not see them losing four games. I hope that I am wrong, but I do not see it happening. I am just telling you the facts.
"The only thing that I am focusing on is beating them right now, on Monday night - and we are not conceding that, I promise you."
The Patriots have won the AFC East title in 12 out of the last 14 years, while the Bills have not reached the post-season since 1999.