Swansea City have signed midfielder Jack Cork from Southampton for an undisclosed fee.
The ex-Chelsea trainee, 25, has signed a three-and-a-half year deal.
Cork will not face Saints on Sunday as the deal was completed after Friday's 12:00 GMT registration deadline.
"We pushed in the summer to bring him in and when the opportunity came up again we were very happy to bring him to the club," said Swansea manager Garry Monk.
Cork, who is the son of former Cardiff boss Alan Cork, would have been a free agent in the summer when his Saints deal was due to expire.
Southampton manager Ronald Koeman said earlier this month that the club had offered Cork a new contract.
Cork told Swansea's website: "It had come to the point where myself and the [Southampton] club had gone as far as we could go.
"The opportunity of a new challenge at Swansea is something I'm looking forward to.
"Swansea are a good footballing team who have been very successful over the last few years.
"It's a team I've always looked at and admired, so for me to play in this team is a privilege."
Swansea visit St Mary's on Sunday, but Koeman said ahead of his departure there was "no chance" of Cork playing against the Saints in that match.