Stoke boss Tony Pulis has been looking to increase his defensive options and brought in Robert Huth from Middlesbrough on Thursday.
Pulis is now ready to plunder the North East again for Black Cats stopper Collins, who has made over 160 appearances for the club since joining from Chester City almost five years ago.
The Welshman has started all three of Sunderland's Premier League games this season, but could find his place under threat by Steve Bruce's recruitment drive.
Bruce is waiting to finalise the signing of John Mensah from Lyon and has also confirmed an interest in Hull City centre-half Michael Turner.
That could lead to Bruce being prepared to let Collins move on, with Stoke prepared to offer the 29-year-old a switch to the Britannia Stadium.