ORCHARD PARK - The battle to become Josh Allen’s backup got off to a spirited start Saturday afternoon during the Buffalo Bills’ preseason-opening 34-25 loss to the New York Giants. Mitch Trubisky got the start in what was the final exhibition game in the history of 53-year-old Highmark Stadium and he played the entire first half and produced scoring drives of 65 and 68 yards resulting in 10 points.