(CNN) It was a sight that gave Liverpool fans plenty of reason for concern as the Reds approach the defining week in the club's season.

Leading English Premier League scorer Mo Salah left the field on a stretcher after suffering a head injury in the second half of Liverpool's victory against Newcastle United on Saturday.

Manager Jurgen Klopp has said the forward will be assessed before a decision is made on whether he will face Barcelona in the second leg of the Champions League semifinal on Tuesday, where a 3-0 deficit must be overturned if Klopp's men are to reach the final.

Salah is placed on a stretcher after suffering a head injury against Newcastle.

Salah scores Liverpool's second against Newcastle.

"He was OK," Klopp said after the match, further revealing that the player, who scored Liverpool's second goal in a thrilling 3-2 win, watched the rest of the match in the dressing room.

"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."

In an Instagram post, Liverpool defender Dejan Lovren further eased fans' worries.

"Yes he is okay. (He) just can't remember who I am. Don't worry he will be fine, Mo is a monster," was Lovren's reply to a concerned fan.

Salah's replacement, Divock Origi, was the matchwinner at Newcastle, scoring the late winner which ensures that the English Premier League title will be decided on the final day of the season.

In a blow to Liverpool's Champions League hopes, however, Klopp confirmed that the injured Roberto Firmino would not be fit to face Lionel Messi and co at Anfield on Tuesday.