The choices he makes following their 4-1 defeat at Wembley will not only be important when it comes to improving their performance for the next game, but could also be vital for the season as a whole.
It's questionable as to whether withdrawing the Croatian centre back made any difference, as the side went on to concede two more sloppy goals, but using Can as the stand-in right-back definitely didn't work.
It may not have been a mistake, as it spared young full back Trent Alexander-Arnold the ignominy of coming on in such a torrid game for the Reds, but Can's performance in the position, and the fact it meant moving one of the club's best midfielders out of the centre of the park meant the game went further downhill for Klopp's side.
Going into a new game with fresh set of ideas and fresh personnel is the way forward for Liverpool, and reports suggest that their manager is ready to make the necessary changes.
The change which saw Can shift across to right-back against Spurs involved the rest of the defence moving across to the left. Joël Matip became the left-sided centre-back in place of Lovren, and Joe Gomez was now the right-sided central defender.
Sticking with Gomez in the centre may be a risk given his age and relative lack of experience in the middle of defence at the top level, but the 20-year-old has long been considered a future star in the position, and now is as good a time as any for him to start making regular appearances there.
His inclusion may also mean that Klopp can get his side to adhere to his preferred tactics more effectively. The Englishman's pace will allow for a higher line, which in turn will push the rest of the team further up the pitch and allow for more effective, more efficient counter-pressing.
The closing of space in the opposition half would mean that those pressing from the front have less ground to cover, and can retain their energy for a longer period. The team have appeared to be flagging later on in games of late, and this one personnel change could help with this.
Another alteration which would allow the team to play a high line would be the introduction of Loris Karius to the Premier League side, building on his current role as the club's Champions League keeper. While the German stopper, signed by Klopp, is yet to convince many of his goalkeeping ability, it can't be any worse than the performance Mignolet served up at Wembley, and he is also a far better sweeper-keeper than the Belgian.
With Karius sweeping up behind the defence, and Gomez's recovery pace, the side would be able to play a much higher line than they can currently, meaning their counter-pressing tactics would be much more effective.
Klopp spoke of this after his side’s convincing victory at Maribor in the Champions League – a game which Karius started.
“To score seven goals is wonderful but our counter pressing was also wonderful,” he said.
“I was close to celebrating our counter pressing more than the goals. We chose the right moments to be high up the pitch and cause them problems.”
Given the difference in quality between Maribor and Spurs, it would probably be unfair to make direct tactical comparisons between the two games, but there's no doubt that Liverpool's counter-pressing at the front starts at the back. Having an agile keeper who will venture from his area and help the defensive line will give those in front of him much more confidence to advance and close down the opposition.
There might also be a case for Danny Ward to be given the start. He's been kept at the club when there was the opportunity to give him regular first team football on loan at Huddersfield, and now might be a good time to back up the decision to retain him.
He's the only one of three keepers yet to be given a proper chance, and from the limited game time he has had at the club he looks like he may possess some all-round shot-stopping and sweeping ability.
Ahead of the defence, changes are also needed in midfield, and this could be the real test of Klopp's newfound ruthlessness. The current version of the midfield three lacks guile, creativity, and game intelligence, but a combination of Can, Philippe Coutinho, and Georginio Wijnaldum may provide some of what is missing in this area.
The screenshot below is one of many examples from the game against Spurs where none of the side's three midfielders were shielding the defence. Henderson is watching the thrower, Milner is marking no one, and Can is supporting Moreno when he might not need to, though he might also be thinking about marking the man taking the throw.
Son is allowed to run into space, and staggers the Liverpool defensive line as a result. This eventually leads to the first Spurs goal as the ball drops over Lovren and into the path of Harry Kane.
Though this example is from a throw-in, the same screenshot could be included from most open-play situations, and was also evident at the set-piece for the third goal, when Dele Alli had all the time in the world to volley home as he hung around away from the opposition defensive line.
Can has been Liverpool's best in this position since Klopp arrived, and should drop back into it, even if he's to leave on a free transfer this summer.
Going even further forward, with Sadio Mané still out injured it would make sense to slot Alex Oxlade-Chamberlain straight into the role previously occupied by the Senegalese, which would then allow Coutinho to drop back and create from midfield.
The man signed from Arsenal in the summer has been impressive in a few of his recent cameos, and deserves a start even if Klopp thinks he isn't up to speed with his way of playing. Even if he isn't, he can't be worse than the some of the things seen lately from those who've played under the German for much longer.
Roberto Firmino, Mohamed Salah, and Alberto Moreno can all be retained. Even if one of them is having an off day they are still important for Klopp's overall tactics. Andy Robertson could come in for the Spanish left back as an alternative, but the current incumbent has been one of few consistent players this season and could keep his place.
While the Liverpool manager is rumoured to be planning changes, the extent of these remains to be seen. Changing just a couple of positions may not be enough to stop the rot which set in fully at Wembley, and is in danger of hanging around for the winter if the starting line-up isn't given an overhaul.