Spiller won't be eligible to return to the Bills' active roster until their Dec. 21 game against the Oakland Raiders, meaning his absence will span eight games.
Spiller took to Twitter on Tuesday afternoon, thanking his supporters and stating that he believes the Bills (4-3) will remain in "playoff contention."
After being injured on a 53-yard run in the first half of Sunday's 17-16 victory, Spiller underwent surgery on his broken collarbone Monday.
Tanner, 26, played in 39 games for Dallas from 2011-2013. He has averaged 2.7 yards on 56 career carries and has nine receptions.