Jurgen Klopp will have made it crystal clear to his players that performances like the one produced against Red Star Belgrade on Tuesday night are simply unacceptable.Asked by reporters to put his finger on what went wrong, the Liverpool manager’s response said it all: “I only have 10 fingers…”James Milner, meanwhile, said in his post-match interview that things went wrong “from the first whistle.”“All over the field, we didn't win the ball back well enough and the passing wasn't good enough,” Milner, who captained the Reds at the Stadion Rajko Mitić, added.“In all areas, we didn't start and when you don't start well in the Champions League you can get punished.”Liverpool went into the match as the firm favourites to seal all three points - a win would have left them with one foot in the Champions League knockout stages - but found themselves 2-0 down inside the opening half-hour following a Milan Pavkov brace.The Reds had chances to get themselves back into the contest but failed to take them. Last season’s Champions League finalists must now attempt to pick up points from their upcoming fixtures against Paris Saint-Germain and Napoli to avoid an embarrassing group-stage exit.On what is undoubtedly the most disappointing moment of Liverpool’s season so far, fans were further angered after seeing Lazar Markovic’s eyebrow-raising Twitter activity.The 24-year-old, whose career has stalled badly following his £20 million move to Anfield from Benfica in 2014, was caught liking a tweet celebrating Red Star’s victory over Liverpool.The tweet from Copa 90 star Vuj features rows of Serbian flag emojis and a single love heart.Liverpool fans have reacted pretty badly, it’s fair to say…

Markovic is, of course, Serbian - and part of him obviously feels proud that a team from his country managed to pull off a memorable Champions League victory.

This was Red Star’s first win in Europe’s premier club cup competition since 1992.

However, it’s curious that Markovic is celebrating a Red Star Belgrade victory - against his current employers, no less - when he grew up playing for their fierce rivals Partizan Belgrade.

Work that one out.

Anyway, it can’t be too much longer before Markovic is put out of his misery and moved on by Liverpool.

Even when he turned out for Liverpool’s Under-23 side in September, he angered fans with his lackadaisical attitude. It was as if he could not be bothered.

And now, judging by his Twitter activity, it seems he’s not remotely bothered what Liverpool supporters think about him.