Jurgen Klopp said concussion protocols are taken "really seriously" after revealing James Milner will miss Sunday's league game at Tottenham.
The Reds boss said that Milner reported a problem when the players returned to the pitch after half-time.
"Nobody wants to push a player through with a concussion," Klopp said.
"It is difficult. It is not that easy because you need two sources, one is the doctor, one is the patient.
"For me it was clear; he got a real check on the pitch and he was fine when it happened.
"In the dressing room in our meeting, 'Millie' was completely fine and, after calming down, came out into the floodlights and was like 'Whoa, what is going on here?