In a sense, Erik ten Hag is back to where he began at Old Trafford with a loss to Brighton. In others, it is far worse than that. On and off the pitch, the problems are multiplying for Manchester United. A troubled start to the season has already encompassed three defeats and, with Bayern Munich next and the prospect of a fourth, it threatens to become a terrible one. A disastrous result was accompanied by dissent in the stands. Ten Hag had carried the Old Trafford crowd with him when he won his power struggle with Cristiano Ronaldo. But when he substituted his new £72m forward Rasmus Hojlund for Anthony Martial, the decision was met with whistles and boos. It was a rare public rebuke of a manager who has been popular but United have faced three probable top-half sides this season and lost to them all. On this evidence, Brighton look likelier to get a top-four finish. Given the ease with which Roberto De Zerbi’s wonderfully incisive Albion eviscerated United, it was hard to argue that the absence of Jadon Sancho, last spotted watching the Under-18s as he is punished by Ten Hag, was the reason for defeat; nor that of Antony, the Dutchman’s costliest signing who is on a leave of absence while he addresses serious allegations of assault by three women. But for a manager who had talked on Friday of setting standards, those on the field of play have been too low in an increasingly shambolic beginning to the campaign. Ten Hag had also lost his first game in charge to Albion. But, 13 months on, with £400m spent in his reign, with an initial 11 who arrived for £347m, defeat to a patched-up Brighton side whose starting 11 cost a mere £20m was more damning. For all United’s trials and tribulations, their injuries and absences, this ought to have been a fine time to face Brighton. For various reasons, none of Evan Ferguson, Solly March, Joao Pedro, Billy Gilmour or Pervis Estupinan began at Old Trafford. Instead, Simon Adingra marked his first Premier League start with one assist, Tariq Lamptey his first in six months – and when playing out of position on the left – with two. There was a certain predictability to two of their scorers: Danny Welbeck, sold by Louis van Gaal, has found the net against United under their last four permanent managers and Pascal Gross, whose seventh goal against them continued his status as their unlikely scourge. Pedro came off the bench to add the third, completing another act of catalytic brilliance by De Zerbi. United, though, had another day when plans backfired. Lacking a right winger, Ten Hag switched to a midfield diamond, using Hojlund and Marcus Rashford as wide strikers. The Mancunian was dynamic, bringing everything but the goal, but the narrow shape left United’s full-backs exposed. Brighton, brimming with counter-attacking menace, created all three goals on the flanks. For the first, the debutant Sergio Reguilon, an emergency signing on deadline day, was found wanting. For the other two, Diogo Dalot was afforded too little protection. The centre-backs were fooled by dummies for goals, Victor Lindelof for the first, the similarly out-of-form Lisandro Martinez for the second. United ended up playing with Lindelof as a lone central defender and required an injury-time save from Andre Onana to stop Ansu Fati from adding a fourth Albion goal. It was still Ten Hag’s heaviest home defeat. His more chastening days had tended to come on the road while United went 20 league games unbeaten at Old Trafford. Now, home and away, Brighton have four consecutive league wins against United; virtually every Albion supporter can recall a time when that would have sounded inconceivable. Not now. They were deserving winners and showed the clinical touch United lacked. First Welbeck completed a one-two of sorts with Adingra, releasing the winger and meeting his cutback with a neat finish. The other crucial contribution came from Adam Lallana, who dummied Adingra’s cross. On his first start since January, the veteran’s footballing intelligence was apparent. On the first start of his Premier League career, the youngster had an assist. Then Gross had latched on to Lamptey’s pass and fooled Martinez before beating Onana. Pedro found the top corner after another Lamptey pass. United’s response came from a rookie. Hannibal Mejbri, brought on with Martial, rifled in United’s only goal from 20 yards. Another should escape the harshest of the criticism. Rashford was electric, if unable to apply the final touch. He had one shot saved by Jason Steele, another deflected onto the bar by the sliding Joel Veltman. A third flew just wide, a fourth was rifled into the side netting. Hojlund celebrated a first United goal, prodded in from Rashford’s low cutback, until VAR ruled the ball was out of play before the Mancunian crossed. If it was the first decision involving Hojlund, who showed a couple of promising touches, to irritate the majority at Old Trafford, it was not the last. His departure brought jeers. It may not be a tipping point for Ten Hag just yet. But United, no strangers to a crisis over the last decade, could soon find themselves teetering on the brink of another. Read More Erik ten Hag says he inherited Manchester United with ‘no good culture’ Erik ten Hag unsure whether Jadon Sancho will play for Manchester United again Liverpool leave it late to come from behind and beat Wolves Erik ten Hag wants to see ‘how strong’ Manchester United are after Brighton loss Pep Guardiola hails impact of Jeremy Doku in Man City’s win at West Ham Roy Hodgson ‘feeling better’ after missing Crystal Palace defeat at Aston Villa