Yeast is in stable condition, Rams head coach Sean McVay said after the game.
Several Rams players, including Jalen Ramsey, left Lumen Field almost immediately after the game to see Yeast at the hospital.
A pulmonary contusion, per the Mayo Clinic, is a bruise to the lung tissue that can cause the lungs to fill with blood and make breathing extremely difficult. It's unclear specifically how Yeast sustained the injury.
Yeast started Sunday in place of Nick Scott, which marked his first start of the season.