The Black Cats looked doomed when manager Gus Poyet left the club in March, but former Rangers boss Dick Advocaat steadied the ship and kept the club in the Premier League, avoiding relegation with one game to spare.
Adovcaat now has the job for another year, and the Dutchman will now be looking to strengthen his squad - and that could involve swooping on his former Old Firm rivals Celtic for his compatriot van Dijk.
The 23-year-old centre back has been sensational for Celtic ever since joining from Groningen in 2013, but could now look to move on in order to further his career.
A Premier League transfer could now be on the cards, with Sunderland keen to beat their rivals to van Dijk's signature by offering up Scottish international forward Fletcher in part-exchange.
The 28-year-old scored just five goals this past season, and was in-and-out of the side after Jermain Defoe's arrival, with Advocaat handing playing time to Danny Graham and Connor Wickham too.
With Celtic needing to sign a striker, the club could be tempted to accept a deal consisting of cash plus Fletcher, who would provide a consistent source of goals in the Scottish Premiership.
Six years after leaving Scottish football as Hibernian player to join Burnley, Fletcher could now head north of the border once again - if Celtic accept Sunderland's alleged offer.