The Portuguese Under-21 international, a summer signing from newly-promoted Fulham, was rewarded for his last-gasp winner against Newcastle in midweek with a first Reds start in the 242nd edition of the Merseyside derby on Saturday.
But Carvalho’s afternoon lasted only for 45 minutes at Goodison Park, with the 20-year-old replaced by Roberto Firmino at the interval after being hurt by a cynical challenge from Everton’s Amadou Onana that earned the Belgian – himself the victim of a poor tackle from Virgil van Dijk that Frank Lampard felt was worthy of a sending off – a yellow card.
Klopp has since moved to allay fears that Carvalho will be yet another addition to a Liverpool treatment room that has been bursting at the seams during their worst start to a top-flight season under the German’s seven-year tenure.
“A massive dead leg and very painful,” he told BT Sport. “One of the most painful things you can get – it should settle quickly but we will see.
“We all think it’s the muscle above the knee, with a massive dead leg. It’s very painful.”
Klopp will hope that Carvalho is able to recover quickly, with their Champions League Group A opener against Napoli at the Stadio Diego Armando Maradona looming on Wednesday night.
The Liverpool boss confirmed that he hopes Thiago Alcantara will resume training at Kirkby on Monday after a thigh injury suffered on the first day of the season at Fulham, though it remains to be seen if the turnaround to Naples will prove too tight for the influential midfielder.
Liverpool were boosted by the return of Diogo Jota to their matchday squad against Everton, while Arthur Melo – a deadline-day loan signing from Juventus – was an unused substitute after his international clearance came through ahead of the game.
That duo will be in contention for Napoli, though Klopp is evidently not expecting anyone else back, with captain Jordan Henderson (hamstring) having joined Ibrahima Konate, Naby Keita, Alex Oxlade-Chamberlain, Calvin Ramsay and Caoimhin Kelleher on the sidelines.
Darwin Nunez returned from suspension to spearhead Liverpool’s attack at Goodison, denied a third Reds goal by a superb save from man-of-the-match Jordan Pickford, who tipped his fierce volley onto the crossbar before half-time.