Hull City midfielder Ryan Mason is in hospital after suffering a head injury during Sunday's defeat at Chelsea.
Mason, 25, clashed heads with Chelsea defender Gary Cahill 13 minutes into the Premier League match.
He was carried off on a stretcher wearing an oxygen mask after receiving eight minutes of treatment.
Goals from Diego Costa and Cahill gave the Blues a 2-0 victory as they moved eight points clear at the top of the Premier League.
Hull boss Marco Silva said he did not have news of Mason's condition but confirmed the player was in hospital.