Liverpool manager Jurgen Klopp was left frustrated on multiple fronts after Saturday's hectic 2-2 draw in the Merseyside derby, questioning the Video Assistant Referee (VAR) over incidents involving Virgil van Dijk and Sadio Mane.
The Dutchman was forced out of the clash with Everton after being on the receiving end of a reckless first-half tackle from goalkeeper Jordan Pickford. Van Dijk gingerly walked off the pitch in the 11th minute with a knee injury before Joe Gomez replaced him.
The defensive stalwart was ruled offside on the play, negating a possible penalty. VAR still could have ruled Pickford needed to be punished, but the netminder escaped a booking, much to Klopp's surprise.
"It was a clear penalty I saw and then we saw the flag went up. I thought they would still look at the foul but that didn't happen," Klopp said post-match. "I don't want to say Jordan Pickford wanted to do it but it is not a challenge how a goalie can do in the box.
"Virgil played I don't know how many games in a row, he plays with pain, but he couldn't play on and that's not good."
Replays showed the defender's right knee buckling awkwardly during the challenge.
The Reds then thought they had won the match in the waning minutes, but Jordan Henderson's stoppage-time goal was chalked off when VAR adjudged Mane to have been just barely offside during the buildup.
The borderline ruling left Klopp puzzled.
"I am a real supporter of VAR - the picture I saw there is no offside, since then I have had 10 interviews and everyone tells me it was not offside and that doesn't lift my mood," the German coach said.
"I didn't see offside but maybe somebody will explain it to me. The picture I saw was not offside, but it was offside because somebody decided it."
Liverpool will seek an explanation regarding both decisions from the Professional Game Match Officials Board (PGMOL) - the organization that oversees referees and VAR - reports Mark Ogden of ESPN.