Manchester United were beaten 3-0 by Liverpool at Old Trafford as the pressure increased on Erik ten Hag following a disappointing start to the season.

United have lost two of their first three Premier League fixtures as they head into the September international break and having only narrowly held on to his job this summer, Ten Hag is already back under pressure.

A first-half double from Luis Diaz put Liverpool in control and Mohamed Salah added a third after the break to seal a comfortable victory against a desperately disappointing United.

Casemiro was at fault for both of Diaz's goals and he was replaced at half-time by Toby Collyer, with his role in the team under further scrutiny after the signing of Manuel Ugarte.

Ratcliffe's vindication

United's victory against Liverpool in the third game of Ten Hag's first season came on a night when Casemiro was unveiled on the pitch before kick-off. Just a week or so over two years later the Brazilian was waiting in the dressing room while his replacement was given the same treatment.

Manuel Ugarte's unveiling got Old Trafford in the mood and they would have reviled in seeing their new Uruguayan on an afternoon when they hoped to make the Scousers cry, as the Stretford's End tribute to Diego Forlan used to say. Unfortunately, any tears shed would have been for the end of Casemiro's career as an elite-level footballer. The Saudi Pro League transfer window closes on Monday but the Brazilian hardly made himself look like a steal on PS300,000-a-week.

He has got through the first two Premier League games of the season, but did see his pocket picked against Brighton. Against Liverpool, he was ruthlessly exposed in a first half that lasted 50 minutes. That was 49 too long for Casemiro, a five-time Champions League winner whose game has regressed at an alarming rate.

He gave the ball away for Diaz's first goal and was pickpocketed again by Diaz for the second. His passing was awry, he couldn't cover the ground sufficiently to make up for a midfield that was again missing in action and just looked to be finished at this level. That he was replaced by a 20-year-old with only 30 minutes of senior football under his belt was telling.

United will now hope Ugarte gets some game time with Uruguay during the international break and is ready to go against Southampton. Starting Casemiro again in a holding midfield role is impossible to countenance right now.

The PS60m deal to sign from Real Madrid was lauded during his impressive first season, but Sir Jim Ratcliffe was already questioning the value of that kind of outlay on a player in his 30s as he went through the books ahead of his investment. As he sat in the directors' box on Sunday afternoon, the vindication would have hardly felt worth it.

Zirkzee's impact

Joshua Zirkzee got his United career off to the perfect start when he scored off the bench against Fulham but after graduating to the starting XI against Liverpool, this was a reminder that he remains a player of raw ability.

Zirkzee forced Alisson into a couple of second-half saves and his work rate encouraged Old Trafford, but there were also moments when he gave the ball away, often through taking the wrong option as an attack built. He will improve for afternoons like this, but United could do with a little more sharpness in attack. Part of this game came down to ruthlessness in the penalty area and United were sadly lacking there.

Zirkzee's game differs from that of Rasmus Hojlund, but he is in a similar position career-wise. He posted similar numbers at Bologna to Hojlund at Atalanta. He is a player with ability and potential but still gaining that top-level experience. Hojlund, when fit, is likely to have come on for his first season in Manchester. United will hope Zirkzee goes through a similar learning curve.

Mount's influence

Asked before the game who would press in the absence of Mason Mount, Ten Hag gave a simple answer. "Bruno and Josh," was the obvious riposte, given the enforced change saw Zirkzee come in for Mount.

But whether it was a deliberate ploy or not, the pressing was nowhere near as intense and aggressive as it had been against Fulham and Brighton. Zirkzee and Bruno Fernandes would sit off, closing passing angles and allowing the defenders to have the ball. That's a mistake when your back four includes two outstanding passers of the ball in Virgil van Dijk and Trent Alexander-Arnold.

It allowed Liverpool to dominate the game. They had it too easy and won the battle for control without any real fight for it. How United missed Mount, not just for his pressing, but for the energy he has brought to performances so far this season. Without him, United's midfield allowed their opposite numbers the freedom of Old Trafford. They made the most of it.

Defensive subs

For the fourth time in three games, Ten Hag made a defensive change during this game and he did so at a time when Matthijs de Ligt had joined Lisandro Martinez in the referee's book.

De Ligt chopped down Diaz as he broke away down the left and after a good first-half performance against Diogo Jota, this was the moment for him to be replaced by Harry Maguire. In truth, Martinez was probably poorer than De Ligt was, with his passing going awry at times.

It would be a surprise if De Ligt doesn't keep his place for the trip to Southampton, but the defensive reshuffles aren't instilling confidence at the back.

Rashford under pressure

When Alejandro Garnacho's number went up with United 3-0 down the first signs of dissent tumbled down from the stands. United fans were furious at one of their brightest attackers going off as they chased the game, not that either winger had had much of a game for the first 70 minutes.

The boos were aimed at the substitution and will rightly be interpreted as frustration at Ten Hag, but there is also the unmistakable sense that the player the supporters wanted replacing was occupying the other wing. It would have been interesting to see the reaction had Marcus Rashford's number gone up instead.

There had already been one vocal show of frustration with the forward when he backed out of a one-on-one with Ibrahima Konate, even if it seemed a race Rashford was unlikely to win. More anger came when he passed inside rather than taking on recently introduced right-back Conor Bradley.

Rashford did create two chances for Zirkzee, but there were times when this was a flat performance from a player who must have kept his place in the team by the skin of his teeth. He is seriously under pressure at United.