Milan Pavkov scored in the 22nd and 29th minutes as the Serbian champions earned a first win in their debut appearance in the Champions League group stage.
"We can perform a lot better than the two [away] games we've had, they've been off days and we need to look at that, of course we do".
However, it would be preferable to avoid a nail-biting Anfield finale which would require them to beat the Serie A side by two goals to overturn their head-to-head record against Carlo Ancelotti's team.
Liverpool have officially revealed their starting eleven and substitutes to take on Red Star Belgrade in an away Champions League group stage clash this evening.
Robertson accepts they have not been at their best over the last three months and that the high standard they set in the previous campaign is now what they will be judged on. 'We have had enough chances to get back into the game and we didn't take them.
It may be a little harsh as Lallana was excellent for Liverpool during Klopp's early years at the club but a succession of injuries have taken their toll and it remains to be seen whether the England global will be able to return to his best form.
On whether he's concerned at Liverpool losing both away games so far in the group... The visitors give possession away cheaply once more and they are in deep trouble now. Firmino drifts to the left byline and fires in a cross that Mane can't get enough on to stab home from close range.
The manager said the striker's horror miss changed the game. "They deserved it with the passion they showed". Tonight when we saw he would play, for us it was clear it would be in a specific way different because he is a proper target player for Red Star.