C.J. Spiller placed on short-term IR

— -- The Buffalo Bills placed running back C.J. Spiller, who suffered a broken collarbone in Sunday's win over Minnesota, on injured reserve Tuesday with a designation to return.

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.

With Fred Jackson also sidelined for possibly a month with a groin injury, the Bills signed former Dallas Cowboys running back Phillip Tanner on Tuesday.

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.

Spiller also tweeted Tuesday that he has faith in teammates Anthony Dixon and Bryce Brown, who both are candidates to see substantial playing time at running back.