Mourinho might also consider the fact that Klopp's men are in far better form than they were back in October, having won four of their last five games and scored 13 goals in the process.
Negating their counter-attacking threat will be vital if United are to stop Mohamed Salah, Roberto Firmino, and Sadio Mane from causing problems.
United head into the game knowing a draw would keep them two points above their rivals and consolidate their position behind City.
Catching Pep Guardiola's side already looks like an impossibility, so would another draw against a team with a formidable record against the top-six really be an unacceptable result?
The reality is that Manchester United supporters are unlikely to accept such conservatism at home.
Mourinho might feel he can justify his defensive tactics in away games against their rivals, but at Old Trafford it's different.
He will be expected to prioritize victory rather than simply avoid defeat.
Go for the jugular?
Many will be eager for Mourinho to release the shackles and take the game to Liverpool.
United have some of the most exciting attacking players in the country.
Is deploying as many of them as possible the best way to get at a Liverpool defense which remains susceptible to collapse?
History suggests it would be a risky approach.
Liverpool have scored more goals from fast breaks than any other Premier League side this season, according to Opta, with Arsenal and Manchester City among the sides to have been punished for over-committing in the attack.
Mourinho will also be wary of what happened in United's visit to Tottenham at the end of January.
The Portuguese named an uncharacteristically attacking team that day.
Many fans welcomed the presence of Alexis Sanchez, Romelu Lukaku, Anthony Martial and Jesse Lingard in the same starting line-up, but Paul Pogba and Nemanja Matic were duly overrun in midfield and United were soundly beaten 2-0.
Learn from Spurs?
On Sunday, the challenge for Mourinho will be to find the right balance.
Play it too safe and he will risk the ire of supporters and invite more pressure onto the team.
Be too gung-ho and Manchester United risk being ripped apart on the counter-attack.
Mourinho would do well to study Tottenham's 4-1 win over Liverpool in October.
Klopp's side went into that game having put seven goals past Maribor in their previous fixture, but Mauricio Pochettino was able to blunt their attacking threat while giving them a taste of their own medicine on the break.
Spurs only had 36 percent of the possession that day at Wembley but frustrated Liverpool by dropping deep and maintaining a disciplined defensive structure.
The back three of Toby Alderweireld, Jan Vertonghen and Davinson Sanchez were flanked by Serge Aurier and Kieran Trippier and protected by Harry Winks, Christian Eriksen and Dele Alli.
They were hard-working and difficult to break down, but what's crucial is that they were also a constant threat from turnovers.
Pochettino's men were instructed to counter-press Liverpool and play the ball forward for Harry Kane and Heung-Min Son as quickly as possible whenever they won it.
By playing so directly, Spurs were able to catch Liverpool out of position, exploit spaces and provoke defensive errors repeatedly.
And despite the visitors' dominance of possession and the fact they made nearly twice as many passes as the hosts, Spurs managed 11 shots from inside the box compared to Liverpool's four.
Mourinho certainly has the tools at his disposal to do something similar.
Manchester United have shown defensive frailties in recent weeks, but the midfield has been bolstered by Scott McTominay's emergence alongside Matic, and there is certainly no shortage of pace on the break.
Martial's availability is uncertain after he missed the 3-2 win over Crystal Palace due to injury, but in Lukaku, Sanchez, Rashford, and Lingard, Mourinho has plenty of options to trouble Liverpool in the same way Spurs did.
By achieving that on Sunday, he could propel United to a valuable victory and avoid another round of debate around his tactics.