The Bills also cut loose center Kyle Mutcher.
The cuts were announced on Wednesday, three days after the team completed a weekend minicamp for rookies and players with fewer than three years of NFL experience.
Mendenhall was signed in April and had no NFL experience a year after completing his college career. He has been signed and released by the Colts and Eagles as well. His younger brother starred at Illinois and rushed for over 1,000 yards for the Steelers last season.
Walter Mendenhall rushed for 811 yards and 11 touchdowns in his one and only season at Illinois State in 2008. He had transferred from Illinois.
Mutcher, an undrafted rookie free agent out of Weber State, signed with Buffalo earlier this month.
Information from The Associated Press was used in this report.