Spiller is coming off a strong training camp after being drafted by the Bills in the first round, ninth overall, out of Clemson. Spiller rushed for 122 yards on 26 carries and scored three touchdowns in the two preseason games he played in, while returning Bills running backs Marshawn Lynch (ankle) and Fred Jackson (left hand) sustained injuries.
The Bills didn't have a media availability Tuesday, but when practice resumes Wednesday, Spiller is in line to work with the starters and open the season in that capacity, according to the source.
Spiller received a five-year, $25 million contract with escalators that could make the deal worth up to $37 million.
Spiller flashed rare playmaking ability at Clemson, where he scored 51 touchdowns in four seasons. He also tied the NCAA record for career return touchdowns with eight.