Darren Fletcher has left West Brom to join Stoke City on a two-year contract.
The midfielder will move to the Potters when his Albion deal expires at the end of the month.
Fletcher had been in contract talks with the Baggies, having triggered a one-year option in his favour earlier this season, but has opted not to extend his two-and-a-half-year stay.
The Scotland international told Stoke's official site: "It's all happened incredibly quickly, but I am delighted to be here.
"This is a fantastic Club with a top manager and a great group of players and I am really looking forward to this opportunity.
"I loved every moment of my time at West Bromwich Albion and I loved every moment of my time with Manchester United, but this is a new challenge for me now, and I like to think I respond well to new challenges."
Albion boss Tony Pulis had been confident Fletcher would stay at The Hawthorns but his departure is a major blow to the manager.
He made 97 appearances for the club and was handed the captaincy within a week of joining from Manchester United in 2015.
Fletcher, 33, follows Saido Berahino to Stoke after the striker moved to the Potters for £12million in January.
He becomes Hughes' first summer signing as he refreshes his squad with record £18million signing Giannelli Imbula expected to leave.
