The Bills' job came open when Mike Mularkey surprisingly resigned last week. Dick Jauron, who finished the season as Detroit's coach after Steve Mariucci was fired, interviewed in Buffalo on Tuesday.
Jauron was the second coach to interview, following Bills special-teams coach Bobby April on Friday.
Other potential candidates, according to the Associated Press, are fired Saints coach Jim Haslett, Chicago Bears defensive coordinator Ron Rivera and Baltimore Ravens offensive coordinator Jim Fassel.
The Saints are expected to introduce Payton as their coach on Wednesday.