Spanish attacking midfielder Juan Mata completed his record £37.1 million (Dh224.5m) transfer from Chelsea to Manchester United on Saturday after completing a medical at the English champions.
United had already confirmed on Friday that they had agreed a deal to sign the 25-year-old for a club-record fee.
“I am thrilled to be joining United. I have enjoyed some very happy years at Chelsea but the time has come for a new challenge,” said Mata, who played 135 times for Chelsea and scored 32 goals after joining from Valencia in 2011.
“United is the perfect place for me and I am excited at the chance I have to be part of the next phase in the club’s history.”
Mata, capped 32 times by Spain, had arrived in Manchester in style on Saturday, landing in the city by helicopter before undergoing his medical.
“Chelsea is a top club and I have many friends there but you cannot turn down the chance to join Manchester United. I look forward to helping the manager and the team be successful in the coming years,” he told manutd.com
United manager David Moyes described Mata as “one of the finest playmakers in the game”.
“It’s a real pleasure to have secured his signature,” he said.
The deal eclipsed the £30.75 million that United paid Tottenham Hotspur in 2008 to sign Bulgarian striker Dimitar Berbatov.
“He’s been instrumental in Chelsea’s recent success, with a notable 28 assists and 32 goals in his last two Premier League seasons,” added the United manager.
“I have been impressed with the excitement he has shown to be part of the new Manchester United. I know our fans have admired Juan for some time now – he has always played well against us – and I know they will be delighted to see him in the red of United, starting on Tuesday (against Cardiff).”
Mata was voted Chelsea’s player of the year in his first two seasons, but he fell out of favour after Jose Mourinho returned to Stamford Bridge as manager last year.
Mata’s signing reflects Moyes’s eagerness to arrest a startling decline in United’s fortunes since he succeeded fellow-Scot Alex Ferguson as manager at the end of last season.
United are currently 14 points behind leaders Arsenal in the Premier League and have been knocked out of both the FA Cup and the League Cup this month, although they have reached the last 16 in the Champions League.
United striker Robin van Persie welcomed Mata’s arrival, writing on Twitter: “Welcome Juan Mata see you all tuesday.”
Centre-back Rio Ferdinand tweeted: “Welcome to my amigo @juanmata10. Hoping you enjoy ya time here and help continue the success at this club.”
Mata will join countryman David de Gea at Old Trafford and the United goalkeeper gave his fellow Spaniard a playful welcome, tweeting: “Welcome to my brother @juanmata10 just one thing ... Not the best clothes.”
Chelsea boss Mourinho said the Mata transfer made sense for the player as well as both clubs.
“I and everyone at Chelsea have massive respect for Juan and his big talent, and when he told us of his wish to move on because he wanted to play more, we did not want to deny him this opportunity,” said the Portuguese.
“We want him to be successful in his career and as well as that, this transfer makes huge financial sense to us at Chelsea.
“We are pleased Juan will stay in England – even with a rival club. He is happy in this country and it is good the Premier League retains such a talented player.”
Meanwhile, reports in the British media on Saturday claimed that United have opened talks with striker Wayne Rooney over a new contract.
The 28-year-old England striker has 18 months remaining on his current deal and was the subject of two unsuccessful bids from Chelsea during the close season.
