David Moyes has promised that the club-record capture of Juan Mata will be "the first of many" new arrivals at Manchester United this year.
The Barclays Premier League champions announced the £37.1million signing of the Spanish playmaker on Saturday evening.
It is a deal which it is hoped will give United's difficult campaign some impetus, with the team seventh in the league and out of both domestic cup competitions.
Talks are under way with striker Wayne Rooney to extend his stay with the club, while there have also been reports of a bid for highly-rated Southampton left-back Luke Shaw as Moyes looks to put his stamp on the squad he inherited from Sir Alex Ferguson.
Moyes said of signing Mata: "This is the first, and there will be many more to come in time. I want the quality of Juan to be the start of it.
"I don't think we will have any more (new signings) in January – I'm still working on it and looking to do so. But hopefully it will be the first of some new signings, some new players who will arrive, more likely in the summer."
The Scot admitted the signing had lifted the mood at Old Trafford.
"Undoubtedly we could all do with a bit of a lift, we have not done as well as we would have liked to do. We see this as the start, we have to look to improve and I'm going to try to bring in some new players to make that happen," he said.
"I want to build an exciting team, I want to win and I want to give the supporters something to shout about – I've not done that often enough."
Moyes, who said he would probably look to get Mata involved in tomorrow night's Premier League game against Cardiff, said it was a surprise the deal was able to be done mid-season.
"I never felt that we would get that opportunity, I wasn't sure that Chelsea would ever sell him to us. Thankfully we got there and I am delighted he is here.
"I'm a bit surprised because it's not something that tends to happen especially between Premier League teams. I was surprised when it happened but we have got a really exciting player, a player I'm looking forward to working with, a player I think everybody in football looked at and says he did a great job for Chelsea.
"I'm looking forward to seeing him in a red jersey and doing it for us."
Mata will be formally presented as a United player at lunchtime at the club's training ground, but gave an interview to in-house channel MUTV in which he too expressed surprise that Chelsea had been prepared to let him go.
"To be honest I think it's a bit surprising, but I have to say I am really grateful to Chelsea – to the owner, to the people working in the club and to the fans. The last six months were difficult for me, I didn't play as much as I wanted to," he said.
"I understand that football is a team sport and I respected that situation. But the chance to come to Manchester United was a great chance for me to carry on with my career, they are a massive club."
Mata revealed he had been in contact with United goalkeeper David de Gea, a team-mate at international level.
"He had been texting me the last five or six days, asking me 'when are you coming, when are you landing? Are you coming by helicopter or by bicycle?'," he said.
"At the end I am very happy to be with him. He's a very good friend and an amazing goalkeeper, so he is important for me."
Mata's capture – and Moyes' confidence that there will be more to follow – indicates the willingness of the Glazer family to invest in the squad in a bid to allow them to keep pace with title challengers Manchester City, Arsenal and Chelsea, if not this season then certainly in the future.
Mata insists he has come to United to add to his trophy haul.
"I would like to win the Premier League," he said. "It's a very, very special trophy and I think at this club you can achieve anything. I am young and I have been lucky enough to win some trophies but I want to win a lot more."
Juan Mata's Open Letter
Juan Mata left Chelsea as a two-time player of the year on Saturday night after the Blues sold him to Manchester United.
Here, Belfast Telegraph Sport picks out some of the choice quotes from his lengthy goodbye letter to Chelsea fans.
Thanking the fans
"I will never forget all the affection given to me by the Chelsea fans. From the very first day until the last. With your support and affection I have grown up as a player and I have had an amazing time both on and off the pitch. I will always feel the gratitude towards you. Always."
On winning European trophies to being out of the first-team picture
"There have been plenty of good moments: the FA Cup, my first trophy as a Blue; the immense happiness of winning titles for the first time in the club's history, such as that magical Champions League night in Munich and the Europa League... On the other hand, I have experienced some complicated situations from a personal point of view, mainly during the last six months."
On why he accepted the move to Manchester
"I believe this is the best choice in order to carry on with my football career and to keep enjoying this sport. Before last summer, my intention was to stay here for a long time; as long as the club wanted me to, and to keep winning trophies for Chelsea FC.
"However, as you all know, things changed after the pre-season. From feeling like an important player, I started to experience some difficult situations and I felt unable to help the team to the extent that I wanted and was used to."
On Mourinho, who oversaw his exit
"(Thanks) to Jose, for making me a stronger player, because in difficult moments, I have learnt to remain positive and to keep working hard. Lastly, I want to thank the club, and in particular its owner, Roman Abramovich, for signing me."
Key questions surrounding Juan Mata's move to Manchester United
Why has he been allowed to leave Chelsea?
Adored by Chelsea's fans he had all the making of a future great, but the arrival of boss Jose Mourinho from Real Madrid last summer changed the dynamic of his role at the club.
Told by the coach that his defensive work was not cutting it, he fell behind Eden Hazard, Oscar and Willian in the pecking order and never managed to convince Mourinho it should be any different. He tried hard in training but it was to no avail.
Mourinho said after a win at Southampton over Christmas that his door was open with regards to Mata's future and that put the writing on the wall.
Where will he fit in at Old Trafford?
Some have asked if the problems Mata has experienced under Mourinho will transfer with him. It is hard to see how.
United are not signing him to shore up their defence. They are woefully short on creativity and need goals from midfield – just 20 per cent of their goals this season have come from there.
To coin a phrase, beggars cannot be choosers and United – with fans critical of the likes of Nani and Ashley Young – need players of Mata's quality.
Expect him to play just behind Robin van Persie and Wayne Rooney – the architect of United's attacks.
What does it say about Moyes?
Moyes has clearly struggled since replacing Sir Alex Ferguson and his first transfer window in the summer was one to forget.
This signing, while not hard to scout, shows he has learnt. He moved quickly and clinically to get the deal done and it demonstrates that he has identified quickly a problem area in the squad he inherited.
Does it mean Mourinho no longer views United as a threat?
Mourinho all but ruled United out of the title race last weekend and even the most loyal Red would surely agree. That said, they will almost certainly come back in future years.
In the short-term, the Blues manager has spoken of the value of loan striker Romelu Lukaku scoring goals against Chelsea's rivals for Everton and, with United still to play Arsenal, Manchester City and Liverpool, this could be another tactical ploy from Mourinho.
Do United still need to spend more?
Splashing £37.1m on Mata is a step in the right direction, especially to appease the fans who have accused the club's owners of not being willing to trade heavy blows.
Mata alone cannot fix United, though. Their defence remains a real concern, especially with contractual doubts about Patrice Evra, Rio Ferdinand and Nemanja Vidic. It could be argued that they need at least two new defenders and another midfielder to go with Mata, but he is at least a start.
The names that have been spoken about are Southampton full back Luke Shaw and Juventus midfielder Arturo Vidal. United are also believed to looking at Newcastle's Yohan Cabaye, Bayern Munich's Toni Kross and Dortmund's Ilkay Gundogan.