Athletic Bilbao midfielder Ander Herrera will complete a £28 million transfer to Manchester United.
United have triggered Herrera's buy-out clause and the Spanish midfielder will become the first official signing of the Louis van Gaal era.
The club attempted to sign Herrera during a chaotic summer transfer deadline day last year, which involved three "impostors" acting on behalf of a Spanish law firm. Ultimately, United were unwilling to meet Herrera's €36m buy-out clause.
Then-United boss David Moyes also had bids rejected for Sami Khedira and Daniele de Rossi on the same day, as he eventually had to make do with the £27.5m arrival of Marouane Fellaini.
Fellaini was United's first central midfield signing in six years yet following a dismal debut campaign, as well as doubts about his future under Van Gaal, United's midfield is arguably in a worse state than it was a year ago.
Tom Cleverley, Darren Fletcher and Michael Carrick are all out of contract in 2015 and it would represent a surprise if any of them were rewarded an extension. Misfit Anderson, whose contract also expires next year, is unlikely to play for United again.
Herrera, who excelled against United in Athletic's 2012 Europa League round-of-16 victories, was not named in Vicente del Bosque's Spanish World Cup squad.
He will become the fifth Spaniard to join United, after Ricardo, Gerard Piqué and current players David de Gea and Juan Mata.
The Bilbao-born midfielder's impending move is surprising considering Van Gaal ended United's interest in other players targeted by Moyes. United pulled out of a £20m deal for Toni Kroos decided against bidding for Cesc Fàbregas, having offered Barcelona more than the £30m he joined Chelsea for. William Carvalho also looked certain to join United had Moyes remained.
United remain determined to sign Southampton left-back Luke Shaw, with at least two other signings desired. Van Gaal wants to bring in Borussia Dortmund centre-back Mats Hummels, while Bayern Munich midfielder Bastian Schweinsteiger and Juventus' Arturo Vidal have both been linked with moves to United.