There is uncertainty over the long-term future of current number two Anders Lindegaard, with rumours that the Dane may seek a move elsewhere. Should that happen, United will need an understudy to David De Gea. Begovic has been the goalkeeper most consistently linked with a move to Old Trafford, but whether the Stoke City stopper would want to trade first team football to play understudy remains to be seen.
Manchester United looked formidable in the defensive department as the season went on and have a wealth of options at centre-back. With Rafael coming on hugely last season, if there is a weakness at the back, it is on the left hand side. 32-year-old Patrice Evra has his critics and bringing in Baines to replace him would provide United with arguably the best left-back in the country. Having been signed by and worked with Moyes, a rekindling of their relationship at Old Trafford would seem a realistic proposition.
Another Everton player linked with an immediate switch to work with his former manager is Belgian powerhouse Fellaini. The 25-year-old has been hugely impressive since joining Everton from Standard Liege in 2008 and could provide some of the physicality and work-rate in midfield that Moyes instilled at Goodison Park. He's been coy over his future in the past, but did recently state that his 'destiny is at Everton'. When United come calling though, loyalties can be tested.
Manchester United love pinching Tottenham's best players - Teddy Sheringham, Michael Carrick, Dimitar Berbatov... Should they sign Bale though, it would trump the lot. The Welshman has just enjoyed the best season of his career, winning multiple awards and so nearly steering his current club into the Champions League. However, Spurs missed out on a top four finish and that has sent transfer speculation into overdrive. United would face stiff competition from Real Madrid, they would need to stump up a huge amount of money and would need to somehow convince Spurs to sell. In other words, it's a long shot.
Another option for United might be a former Tottenham player in the shape of Modric. Since leaving White Hart Lane for Real Madrid last summer, the Croatian has struggled. Voted the 'worst signing of the summer' in a Spanish newspaper poll, the 27-year-old has been linked with a swift return to the Premier League. While he may not have enjoyed a great season at the Bernabeu, his sublime goal against Manchester United in the Champions League proved he's still got it.
When Fabregas left Arsenal for a return to his boyhood club, it appeared a move for life. But two years down the line and a failure to cement a place in the starting line-up has led to speculation the midfielder could leave this summer. Moyes has reportedly targeted a central midfielder as his primary concern, and Fabregas would fill the Scholes shape hole at Old Trafford brilliantly. Should Barca be willing to sell, Arsenal will have first option on him, which could prove a stumbling block.
If it's not Fabregas joining from Barcelona, perhaps it will be his team-mate Alcantara. The 22-year-old is one of the most exciting talents emerging at the Nou Camp, but with Xavi, Iniesta and Fabregas ahead of him, opportunities have been limited for the Spain international. There are also rumours the central midfield player has a buy-out clause of 18 millions Euros.
Angel Di Maria
Another option for Manchester United could be Argentina international Di Maria. He's been in and out of the Real Madrid side in a turbulent season but his pace and creativity are not in doubt. He would reportedly cost in the region of £17m, while PSG are also said to be sniffing around.
Juventus and Italy midfielder Marchisio has shown the kind of creativity for both club and country that Moyes would be interested in. A fee in the region of £21m has been touted if someone wants to prise him away from the Italian champions. The Turin side are reportedly open to selling in order to raise funds for a new striker - possibly Zlatan Ibrahimovic.
The name of Ajax midfielder Eriksen has been knocking around the rumour mill for some time now and it would seem the 21-year-old central midfielder will finally make a move this summer. But where? It appeared he was on the verge of a move to beaten Champions League finalists Borussia Dortmund at one stage, but the Denmark international recently said there were other 'options' open to him. Those 'options' are though to be United and Liverpool.
Manchester United have signed numerous players from Portugal before and could be heading back to sign Benfica star Gaitan. Back when Ferguson was in charge, it was reported the Argentina international was one of the club's top summer targets. Whether that remains the case is unclear. If they do firm up their interest, the 25-year-old would cost in excess of £25m - United better be sure they want him.
Gaitan is not the only Benfica player linked with a move to Old Trafford. At one stage it was reported that United had already agreed a £17m deal for their central defender Garay. That was before United's existing defence put in such a strong finish to the season and since then interest in the Argentina player is said to have cooled.
And if United don't get either of those two, perhaps they will sign Matic. The midfielder has proved a big hit at Benfica since he was dumped by Chelsea in 2011 after two frustrating seasons at Stamford Bridge which yielded few opportunities. In the Europa League final in May, despite ending the match on the losing side, his vibrant display proved Chelsea may have made a mistake in letting him go. The 25-year-old Serbia international has also been linked with Monaco.
Lewandowski is probably the hottest striker in Europe right now - four goals against Real Madrid will do that. United have been linked with him for quite some time now and continue to be so. Yet a switch to Bayern Munich for the Borussia Dortmund forward appears almost certain, meaning the Poland striker won't be on his way to Old Trafford.
All the talk this summer has been about the return of Real Madrid manager Jose Mourinho to Chelsea. Yet the return of Real Madrid's star player to Manchester United would blow that story out of the water. The Portugal international claimed he was 'sad' earlier in the season, a claim bourne out of his frustration at not being the best paid player in the world apparently. That has led to speculation he could leave the Bernabeu this summer and one potential destination would be United. Real will do everything to keep hold of him, and it seems more than likely he will remain where he is.
A cheaper option in the strike department would be Heung-Min. The South Korean forward has enjoyed a breakthrough season at Hamburg that has alerted a number of clubs to his talents. While Manchester United have been linked with the 20-year-old, so have Chelsea and Tottenham, with the latter said to be particularly keen. Borussia Dortmund are also lining up a move according to reports.
Manchester United may have just won the Premier League at a canter, but that doesn't mean they won't be making additions this summer.
David Moyes has an incredible array of talent already at his disposal, but he'll want to put his own stamp on the squad and that means big names could be arriving at Old Trafford over the next couple of months.
Never short of players being linked with the club, here, we round up those rumoured to be on their to Manchester United.