According to Football League World, the Scottish giants are on standby as Stewart and the Black Cats struggle to agree on a new contract for the talismanic striker.
It is suggested that if the former Ross County man cannot agree to extend his stay at Sunderland further, then they will be willing to cash in on him during the January transfer window, with both Rangers and Celtic keen to bring him back to his native Scotland.
The Scotland international joined in January 2021 and has contributed to 34 goals and eight assists in 72 appearances, playing a huge part in Sunderland’s promotion from League One via the playoffs last season.
Sunderland legend Kevin Phillips was full of praise for the Scottish sensation last season, likening him to another former star in Niall Quinn.
He said: “[He] is turning out to be an excellent signing for Sunderland. I’m a big fan. He is going to be their top scorer this season.
“Every time I watch him he impresses me. He is only going to get better and better.
“He reminds me of Quinny. Quinny was able to rise and find the player. His timing was brilliant and so is Stewart’s.”
He started the new campaign in extremely impressive form, notching five goals and three assists in just seven appearances in the second tier, averaging a superb 7.81 rating from WhoScored for his performances.
Considering Jack Clarke is ranked as the Black Cats’ second-best performer this season with a 7.01 average rating, it is clear just how important Stewart is to Tony Mowbray at the Stadium of Light, and losing him could be the first significant blow the former Blackburn boss has had to deal with during his time at the club.
Given his worrying contract situation at Sunderland, it may be tough for the 26-year-old to turn down the prospect of future European football with Rangers or Celtic back in Scotland, but Mackems everywhere will be praying that he signs a new deal.