Stoke have signed defender Danny Collins from Sunderland for £2.75m.
Potters boss Tony Pulis told the club's official website: "Danny has been Sunderland's player of the year for the past two seasons which speaks volumes for the impact he has had at that level."
Pulis added: ''He can play at left-back or centre-half which gives us further options along the back four.''
Wales international Collins, who joined the Black Cats in October 2004, will join former Black Cats team-mates Whitehead, Liam Lawrence, Thomas Sorensen, Danny Higginbotham and Rory Delap at Stoke.
He said: ''One of the great things about this move is that I will have some familiar faces around me with so many ex-Sunderland players already here. Why, the club even plays in red and white stripes as well.
''All this has happened so quickly because only a few weeks ago I was captaining the Sunderland side in their pre-season friendlies, but Steve Bruce made it clear he was going to bring in new faces and couldn't guarantee me a place.
''Therefore, when I was made aware of Stoke's interest, I thought it was a good time to move on and seek a fresh challenge.
''In many respects the two clubs are alike in that they have big ambitions to finish in the top half of the table this season.''
Meanwhile, the club have confirmed Ipswich have signed Grant Leadbitter for up to £2.6m and fellow midfielder Carlos Edwards for up to £1.35m.