The Reds need to overturn a 3-0 Champions League semi-final first-leg deficit against Barca at Anfield to reach the final.
“Mo got the hip of the goalie in his head and then was on the ground,” said the Reds boss.
“The doctor had to make a decision – on the pitch or off the pitch – and the decision was off the pitch and we accept that of course.
“When we came in, he was sitting in the dressing room and had watched the game. He was then fine but of course we have to wait. He got a proper knock in that situation. We’ll have to see.”
Klopp also revealed that Roberto Firmino will miss Tuesday’s semi-final second leg against Barcelona with a muscle injury.
He was a late substitute in the first leg and missed the entire game against the Magpies.
“He will not be ready for Tuesday and the rest [of the season] we will see,” said Klopp, whose side face Wolves on the final day next Sunday.