By Chris Rosvoglou Buffalo Bills quarterback Josh Allen is officially questionable for this Sunday’s game against the Minnesota Vikings. Allen is dealing with a right elbow injury. He missed practice on Wednesday and Thursday because of it. Fortunately for the Bills, it appears Allen is making progress in his recovery. On Friday, he was listed as a limited participant in practice. With Allen listed as questionable for Week 10, Bills fans will have to wait until Sunday to find out who’ll be under center for their squad. Case Keenum would be the starter if Allen is unable to play. Bills head coa…