Runyan will work out for the Buffalo Bills on Thursday, ESPN.com's Matt Mosley reports.
Runyan never missed a game in nine years with the Eagles, starting 192 straight regular-season contests. He wasn't re-signed after having microfracture surgery on his right knee.
Coach Andy Reid brought Runyan in Thursday to check his fitness level.
Philadelphia revamped its offensive line in the offseason, acquiring two-time Pro Bowl left tackle Jason Peters from Buffalo to replace longtime starter Tra Thomas. Shawn Andrews, a two-time Pro Bowl pick at right guard, was moved to Runyan's spot. Shawn's brother, Stacy, was signed to play right guard.
Shawn Andrews missed the preseason with a back injury but expects to play Sunday.
Matt Mosley is the NFC East blogger for ESPN.com. Information from the Associated Press was used in this report.