Jurgen Klopp appeared to be unhappy with Mohamed Salah's tracking back as he hauled him off just after the hour mark of Liverpool's latest Premier League defeat.
The Reds lost 1-0 to Chelsea at Anfield in a result that further dented their chances of finishing in the top four, with Mason Mount's goal condemning them to a fifth straight home defeat.
As the Reds sought to try and haul themselves back into the game following Mount's opener, Klopp opted to bring off both Salah and Curtis Jones in the 62nd minute, with the pair being replaced by Alex Oxlade-Chamberlain and the returning Diogo Jota.
In the Sky Sports commentary box, former Reds defender Jamie Carragher was stunned by Klopp's decision.
"I'm surprised at Mo Salah coming off, l really am. He doesn't look too happy himself," he said.
" Liverpool need a goal and he is the top scorer in the Premier League."
Salah could be seen shaking his head as he headed for the touchline, and then again as he sat on the bench.
The Egyptian wasn't injured, but Klopp's decision came after he was left frustrated with his failure to track back.
Picthside reporters at the match detailed how, just prior to the change, Klopp was seen bellowing at Salah and asking him to get back and defend, with the forward just jogging back into position.
After a discussion with his assistant Pep Lijnders, Klopp then decided to make the change.
Liverpool have been playing a slightly modified version of their usual formation in recent matches, with right-back Trent Alexander-Arnold more withdrawn and so therefore needing a little more help in front of him.