All the pre-season optimism at Manchester United, generated by Louis van Gaal’s appointment and some impressive friendly results, was quickly wiped out during a dismal opening-day home defeat to Swansea.

The shock 2-1 loss was United’s first defeat at Old Trafford on an opening weekend since 1972 and marked the first time Swansea have ever won there in the league. Following Van Gaal’s arrival, it was hoped last season’s struggles under David Moyes would be quickly forgotten but the Red Devils bore a striking resemblance to the side that thoroughly under-performed in 2013-14.

Slow to start, jittery in defence, sloppy in possession and only flickering into life at times in the final third, United lacked drive and, worryingly, desire against an admittedly well-drilled Swansea outfit. It wasn’t meant to be like this.

Of course, judging a side on one performance is far too hasty and it would be completely ridiculous to write off United and Van Gaal so soon. Opening-day results can frequently be very deceptive – as Moyes’s 4-1 win over the very same opponents 12 months ago proves nicely – but it is clear United have more work to do to get back in the mix for the top four than many people thought before a ball was kicked this season. The fact plenty of pundits (and the bookies) had Van Gaal’s side among the the leading candidates to actually win the Premier League before the action got underway shows just how much faith they had in the powers of the highly-respected Dutch coach but, on the evidence of the Swansea defeat, he has his work cut out. It is telling that their odds for the top prize (see http://www.bet365.com/news/en/betting for more details) went out considerably after the early loss.

Luke Shaw’s untimely injury plus the sale of Patrice Evra to Juventus meant Van Gaal was forced to start rookie Tyler Blackett against Garry Monk’s side and there remains serious question marks over the defence following the summer departures of Rio Ferdinand and Nemanja Vidic. Putting it simply, Chris Smalling and Phil Jones, at the minute at least, simply do not look good enough to be the regular centre-half pairing this season.

Further up field £30m summer signing Ander Herrera seemed to struggle with the intensity of the Premier League in an underwhelming debut, while Juan Mata picked up where he left off at the end of last season – namely looking nowhere near as good as he did when at Chelsea. Only Wayne Rooney (again) came out of the game with any real credit as the England man seemed to thrive with the added responsibility of the captaincy. The fact that Van Gaal had to turn to the much-criticised Marouane Fellaini in the second half as United attempted to get back level underlined the lack of quality in depth, while Ashley Young and Nani also failed to impress.

So it’s clear there needs to be some big-name arrivals at Old Trafford before the transfer window closes. Plenty of top players continue to be heavily linked with United but, frustratingly for the fans, deals still seem some way off.

Angel Di Maria, Daley Blind, Marco Reus, Mats Hummels and Arturo Vidal have all been targeted without so far arriving and there needs to be a serious injection of quality if Van Gaal is to enjoy a better debut season at Old Trafford than his predecessor.