"Roy Keane has bought a few players that people may have looked at but not gone for," Stubbs told evertonTV. "To be fair the ones he has brought in have come up trumps. Kenwyne Jones has done well of late. He's a big lad and has scored a few goals.
"Hats off to him, he has tried to add in the right places this year."
Stubbs spent a short period at Sunderland in the 2005/6 season before returning to Goodison and recognises the importance the Wearsiders attach to being in the nation's top division.
"It is a Premier League club, a big club, and they have probably been deprived of top flight football for too long," said Stubbs.
"The fans have craved it for a long time, especially seeing Newcastle in there.
"They are back and they are doing okay, they'd probably like to see themselves a bit higher but it is always difficult in the first season back."