The performance of Loris Karius in the Champions League could have been a result of a concussion.

Liverpool sent Karius for a head scan at Massachusetts General Hospital last Thursday amid concern at his reaction to a collision with Real’s captain, Sergio Ramos.

Karius made two major errors that led to Real Madrid goals.

A statement released on Monday by the hospital on Dr Zafonte’s behalf and with the player’s permission confirmed that Karius had been concussed.

It read: “On May 31, 2018 Mr Karius underwent a comprehensive examination by Dr Ross Zafonte and Dr Lenore Herget in Boston at Massachusetts General Hospital and Spaulding Rehabilitation Hospital. After carefully reviewing game film and integrating a detailed history – including his reported present and immediate post-contact subjective symptoms – physical examination and objective metrics, we have concluded that Mr Karius sustained a concussion during the match 26 May 2018.