While a 2nd-place finish in the Premier League wouldn't usually be seen as a particularly bad season for Manchester United, the fact that it was a trophyless campaign made it much more disappointing.
A premature last 16 exit from the UEFA Champions League at the hands of Sevilla was frustrating, to say the least, for Red Devils fans, and one of the most boring FA Cup finals of recent times, which they lost, made matters even worse.
It seems as though Jose Mourinho has done enough to hold onto his job for now but a similar season next time around won't guarantee that. With Liverpool and Manchester City strengthening their sides already, United must catch up.
Upon finishing the World Cup with Brazil in Russia in six weeks' time, Fred will join up with the 13-time Premier League champions after signing from Shakhtar for £55 million this week. Diogo Dalot has also signed, from Porto, and the 19-year-old will train at the Aon Training Complex in the next days. Here are four other players they should look at over the summer.
#3 Raphael Varane
The defensive frailties of Phil Jones and Chris Smalling have been highlighted on a number of occasions over the last few years and with Eric Bailly being injured for long periods of last term, a new centre-back is needed at Old Trafford.
One player that should be on top of the list is Raphael Varane, who admitted that he snubbed a move to United in 2011 in favour of a move to Mourinho's Real Madrid. That shows the admiration of the defender towards the Portuguese manager which could help to secure a summer transfer.
Alongside Bailly, the 25-year-old has the potential to form a formidable partnership in United's push for a long-awaited title win. With the solidity of David de Gea behind them, it would be every striker's nightmare to face such a strong trio. Everything should be done to bring the Frenchman to the red half of Manchester and at just over £50 million, it could be a fantastic deal.
#2 Toby Alderweireld
This is a player that the Red Devils have been linked with for a couple of years now as it becomes clearer and clearer that Toby Alderweireld will leave Tottenham in search of a better contract this summer.
As with the aforementioned Varane, the signing of the Belgian would massively stabilise a defence which seemed all over the place on occasion over the past year or two. Also, his price tag is reportedly very similar to that of Varane: just over £50 million. He has experience of playing in the Premier League and seems open to a move so all the signs are pointing in the right direction. As well as the fact that he is a marked improvement on Jones and Smalling, the players he would be replacing should he sign.
How the central defender performs during the upcoming World Cup will be a big factor in any potential offers from Ed Woodward but the 29-year-old's good track record would show that he is more than capable of performing to a top standard in a back four that is largely failing in its current state.
#1 Gareth Bale
When discussing experience of English top-flight football, there aren't many players who offer more than Gareth Bale, who is certainly on the market after struggling for game time over the last 18 months at Real Madrid.
The four-time Champions League winner is exactly what United are looking for as he has everything, as shown previously, to be a massive hit in the Premier League. While he may be older than he was during his time at Tottenham, his match-winning performance in the Champions League final win against Liverpool was more than evidence enough that he is still very much world-class.
The only sticking point is that Zinedine Zidane, who was denying Bale the opportunity of regular starts, has resigned at the Bernabeu meaning his Los Blancos career could be revived by the next manager. However, it would be the blockbuster signing that the fans at the Theatre of Dreams, as well as Ed Woodward, crave.
The lack of a top drawer right winger has been a great thorn in the side of United line-ups of the last few seasons and bringing in a player of this calibre would certainly address that issue.
There aren't any better players in the world that can realistically be signed this summer so Manchester United need to ensure Gareth Bale is their number 1 transfer target.
Which player do you think Manchester United should sign in the summer? Let us know in the comments.