Banner will undergo an MRI to confirm what would be a season-ending injury.
The 26-year-old was hurt in the second half of the Steelers' 26-16 victory over the Giants. He departed the field on a medical cart.
The Steelers named Banner their starting right tackle before their season opener. The offensive lineman beat out Chukwuma Okorafor for the position in training camp. Okorafor will now likely fill in at right tackle in Banner's absence.
The Indianapolis Colts originally drafted Banner in the fourth round in 2017 but cut him before he had the chance to suit up for the franchise. He enjoyed stints with the Cleveland Browns and Carolina Panthers before Pittsburgh signed him in 2018.
Banner tweeted a message to Steelers fans after the game.