Victory would have had Liverpool sitting pretty, regardless of the group's other result later in the day. Klopp's decision to introduce Daniel Sturridge, Adam Lallana and Joël Matip into the starting lineup against Red Star arguably contributed to the disjointed display but Robertson denies Liverpool's focus has wavered outside the Premier League.
Liverpool continued to dominate the ball as Red Star sat back, and Mohamed Salah went close when his 71st-minute effort went behind off the outside of the post.
Almost three decades on, Red Star don't have a household name in their squad and needed to qualify for the group stage through the playoffs. Managing four of those sides, Rafa Benitez (Liverpool 2009/10), Roberto Di Matteo (Chelsea 2012/13), Roberto Mancini (Man City 2012/13) and Louis Van Gaal (Man Utd 2015/16) all lost their jobs either during or at the end of that season.
Things turned from bad to worse for the Reds when Pavkov doubled Red Star's lead with a stunning long range strike in the 29th minute.
"I think it's one of those periods we need to get through", Robertson said.
There were plenty of candidates for worst player, but Daniel Sturridge's terrible first half performance was noticeably awful.More news: Warriors coach Steve Kerr says Zion Williamson could be next LeBron James
Left-back Andy Robertson, playing nearly as an out-and-out winger after the break, saw a cross deflected on to the top of the crossbar, while Salah finally forced a save out of Milan Borjan, hitting a post with his next effort. They arrived in Belgrade in first place in the group but has ceded the initiative and will be overtaken by either Napoli or Paris Saint-Germain, who meet in Naples later Tuesday.
Liverpool remain tied with Napoli at the top of Group C on six points.
Just as in their previous European away game at Napoli, Liverpool were well below par as they slipped to another disappointing defeat.
"You can't give teams that start", Liverpool midfielder James Milner said.
"I do not say it is serious we lost two times, but of course we have to make sure that it will not happen again, otherwise it will be hard, because the next game is already an away game again, and then a tough home game".
We need to come together as a team and try to give what the gaffer wants, try to get the spark and try to win games more comfortably.