Manchester United have agreed a deal worth up to 80 million euros (£67 million, $88 million) to sign Portuguese international midfielder Bruno Fernandes from Sporting Lisbon, the Premier League club announced on Wednesday.
"Manchester United is delighted to announce it has reached agreement with Sporting Clube de Portugal for the transfer of Bruno Fernandes. The deal is subject to a medical and the agreement of personal terms," United said in a statement.
Fernandes, 25, has been linked with a move to Old Trafford for many months, but United were previously unwilling to meet Sporting's valuation.
Sporting confirmed the deal is worth an initial fee of 55 million euros with another 25 million euros in performance-related add-ons.
The add-ons include five million related to appearances, five million dependant on United qualifying for the Champions League and 15 million on Fernandes winning individual awards.
"Some are born great, some achieve greatness, and some have greatness thrust upon them. Thanks captain," Sporting tweeted alongside of video of some of Fernandes's finest moments for the club.
United are badly in need of midfield reinforcements due to long-term injuries to Paul Pogba and Scott McTominay, while a back injury to Marcus Rashford has also left Ole Gunnar Solskjaer short of options in attack.
Fernandes offers a goal threat, having scored 63 goals in 137 appearances for Sporting since returning to his homeland after spells with Udinese and Sampdoria in Italy.
He was also part of the Portugal side that won the inaugural Nations League in June and has scored twice in 19 international caps.
There had been mounting pressure on United's executive vice-chairman Ed Woodward to land at least one marquee name in the remainder of the transfer window.
Woodward, who has overseen the club's poor recruitment over the past seven years, had been the target of the fans' anger in a 2-0 home defeat to Burnley last week.
Police have launched an investigation into an attack on Woodward's Cheshire home on Tuesday night when a hooded group targeted the property with flares and graffiti.
United lie fifth in the Premier League, a massive 33 points behind runaway leaders Liverpool and six points adrift of the Champions League places.
Their chances of a top-four finish will depend greatly on how they fare in their next two league games at home to Wolves on Saturday and then away to fourth-placed Chelsea on February 17.
The Europa League offers another potential route into next season's Champions League and Fernandes will be eligible to feature for United when that competition returns next month despite already playing for Sporting in the group stages.
Fernandes is expected to watch United in action when they travel to Manchester City in the second leg of their League Cup semi-final on Wednesday, trailing 3-1 from the first leg.