How Mourinho's tactical changes exposed Liverpool

Jose Mourinho made it clear before and after Manchester United's win over arch-rival Liverpool that he doesn't care about outside distractions.

"I am a bit tired, we have a match on Tuesday. I don't care what people say. The boys are happy, I'm happy," Mourinho told Sky Sports after his side secured a 2-1 victory at Old Trafford to build a five-point lead on the Reds.

Mourinho didn't even care what his own supporters thought after they shared their feelings with a chorus of boos in response to his decision to remove Saturday's goal-scoring hero, Marcus Rashford, moments after Liverpool cut United's lead in half.

It's a mindset that's benefitted Mourinho since his wildly successful introduction to English football with Chelsea in 2004, when a suffocating defensive scheme took precedence over attacking flair and resulted in the Blues losing only one league game while allowing just 15 goals over the 38-match schedule - 11 goals better than the next best defensive team.

The Manchester United manager, however, showed Saturday that he's willing to deviate from methods that have worked in the past to exploit an opponent.

It became evident that talk of employing a conservative approach ahead of Saturday's match wasn't in Mourinho's game plan as was widely expected. United seemingly ditched the negative style in favour of a more positive method that Liverpool struggled to contain right from the get-go.

Jesse Lingard was initially expected to get the start until Mourinho reportedly settled on giving Rashford his first Premier League start since Boxing Day in an effort to inject some extra pace down the right flank.

The decision paid off almost immediately.

Liverpool's glaring weakness was exposed early and often when Trent Alexander-Arnold struggled mightily to restrict Rashford's blistering runs down the right wing.

Rashford brought the United faithful to their feet 14 minutes into the clash during a run into the box that ended with a slick cut-back that left Alexander-Arnold for dead, before the English forward's powerful strike zipped over Loris Karius' out-stretched hand.

Related: Rashford proves again on big stage why he deserves to start every match

While Rashford rightfully garnered plenty of praise for his composure in Liverpool's penalty area, it was the glancing header from Romelu Lukaku that ultimately resulted in the 20-year-old opening the scoring. Holding up play and acting as an anchorman was a trademark of the Belgian's successful outing Saturday, as Lukaku dominated Dejan Lovren during the majority of their aerial duels.

Lukaku's efforts in the air rewarded United with another goal when he beat Lovren again before laying the ball off to Juan Mata, whose attempt to cut inside resulted in a charging Rashford collecting the deflected ball and scoring his second of the day from inside the box.

Going the aerial route isn't a brand of football normally associated with Mourinho's squad, but it was an effective tool used to bypass Liverpool's potent midfield. The long ball was vital to helping United take control of the match inside the opening half hour, as Mourinho opted against playing from the back in favour of allowing goalkeeper David de Gea to find Lukaku up the pitch with towering goal kicks that eventually helped create Rashord's brace.

Although Mourinho disregarded the notion of external influences, there was one point of contention that the Portuguese manager couldn't ignore after the match. He addressed the smattering of jeers that echoed throughout Old Trafford when supporters apparently would have rather seen Scott McTominay's day end instead of Rashford's.

"I'm not upset with fans about Rashford," Mourinho said, according to the Independent's Miguel Delaney. "I'm upset with fans against McTominay. The kid made all the right decisions and they wanted him to make all the wrong decisions."

McTimominay did everything that was asked of him on a day when the midfielder was selected to replace the injured Paul Pogba in the starting team. Alongside Nemanja Matic, the 21-year-old produced a masterful display in helping contain Liverpool's vigorous attacking unit of Mohamed Salah, Sadio Mane, and Roberto Firmino. The pair consistently thwarted Liverpool's efforts to generate an attack in United's end, often sitting right in front of their own back four and snuffing out any hint of danger with a tackle or clearance to safety.

A similar performance from the entire team will be vital in the crucial weeks ahead, as Mourinho will be desperate to keep pace with Manchester City and avoid watching United's city rival possibly clinch the league title at Old Trafford when Pep Guardiola's men visit on April 7.