Manchester United suffered one of their worst defeats in Premier League history as Erik ten Hags side barely laid a glove on Brentford in a 4-0 defeat on Saturday.Ten Hag was looking for a response to last weekends 2-1 home lo s to Brighton and Hove Albion and was able to hand Cristiano Ronaldo a start, but all United got was a humiliation.David de Gea was at fault twice as Josh Dasilva and Mathias Jensen put Brentford two up inside 18 minutes, before Ben Mee and Bryan Mbeumo ensured Brentford became only the third side to put four past United in the first half of a Premier League game Al Kaline Jersey .While the Bees could not inflict further misery on Ten Hag and United, it mattered little as the damage was already done. United gave Thomas Franks mena helping hand for the opener as De Gea inexplicably let Dasilvas 25-yard effort squeeze into the bottom-right corner after Ronaldo had been robbed.The floodgates then opened.Shortly after United escaped a similar situation, Christian Eriksen was dispo se sed inside his own box following an ill-advised pa s from De Gea, and Jensen applied a disguised finish with 18 minutes played.The off-balance Mee nodded in at the back post as United failed to cope with the hosts physicality, and by the 35th minute it Shane Greene Jersey was 4-0 Dasilva racing onto a clearance to play an exquisite pa s into the box where Mbeumo held off Luke Shaw to score.Ten Hag made three changes at the break and that at least helped stem the flow of goal conce sions.United improved as an attacking threat, with Ronaldopresented with a couple of half-chances andEriksen testingDavid Raya with a header.But still Brentford eased to a Tyson Ross Jersey famous victory.What does it mean? Urgency of Uniteds squad rejuvenation laid bareThe Brighton lo s was bad. This was simply embarra sing. The i sues with Uniteds squad were obvious last season, with Ralf Rangnick suggesting they needed 10 new signings to be competitive.While Rangnick was ultimately cut loose from his deal to become a consultant, it is difficult not to look back on those comments now given how bad United Michael Fulmer Jersey have been in their first two games of the season, and the fact only three new players have come in.Granted, there remains a bit of time in the transfer window, but if United cannot make significant improvements over the next eight days, Liverpool could enjoy another Old Trafford mauling.Thomas Frankly exceptionalWhile Brighton won the midfield battle against United last weekend, they did not do what Brentford did. Frank set his team up to pre s with such intensity and it worked a treat.Dasilvas goal was fortunate but was the result of pre sing Ronaldo, and then Jensens strike was a product of pre suring United as they attempted to play out from the back. The visitors proved they are way off being able to play Lance Parrish Jersey Ten Hags brand of football.David de HowlerIt feels a little unfair to focus on one particular United player because so many of them were poor, but De Geas error for the opener was truly horrific and he needle sly put Eriksen in danger for the second with a pa s that was not on. Those goals gave them a mountain to climb.Whats next?Ten Hags hunt for a first win as United bo s continues a week on Monday with the visit of bitter rivals Liverpool to Old Trafford. Brentford go to Fulham two days earlier.