West Ham have announced the loan signing of Joao Mario from Inter Milan until the end of the season.
The attacking midfielder, 25, goes straight into the squad to face Wigan in the FA Cup this weekend.
"I am really happy to be here. It’s a really amazing experience to join this amazing team and I am just glad to be here," he told his new club’s official website.
"It was a fast move. I have spoken with everyone around the team and, for me, it is exciting to play in the Premier League. I spoke with the coach and for me, I am really happy to be training for an amazing coach, also."
Friday’s announcement was not unexpected, given United boss David Moyes spoke openly about the player at his Thursday press conference.
"My biggest concern is not him as a footballer but getting used to the Premier League, the speed and competitiveness compared to Italy or Portugal," Moyes said.
"His ability as a footballer is not in question, he’s proved it, and I just hope he can hit the ground running. That’s my only concern."
Mario played in all seven games as Portugal won Euro 2016.