Isak joined Newcastle in a £60m move from Real Sociedad in 2022 and scored 27 goals in 42 appearances across all competitions last season.
He helped the Magpies win the Carabao Cup in March before starring as they finished fifth in the Premier League to secure Champions League qualification.
But amid interest from Premier League champions Liverpool this summer, he released a statement in which he said promises had been “broken” by Newcastle, adding their relationship couldn’t continue.
The Magpies denied giving Isak assurances he could leave the club but after signing fellow strikers Nick Woltemade and Yoane Wissa late in the window, accepted Liverpool’s record-breaking offer.
After leaving Newcastle, Isak said he was “forever grateful” to the club.
Burn, 33, who has made 152 Premier League appearances for the Magpies, says he understands the fans’ frustration at how the saga unfolded.
“As a Newcastle fan, you know what Newcastle fans are like – we’re very protective of our club – you want players to be there who want to play for Newcastle,” he added.
“But I’ve been in the game long enough now to understand what goes on and I wish Alex all the best… apart from when we play Liverpool, obviously!”
Burn praised the club’s transfer business during the summer and was optimistic for the rest of the campaign.
“I think we have recruited really well. I think if you look at our transfer window in general, we have got good depth in every position now,” he told 5 Live.
“The club and the board have invested heavily, and it could be a really positive season.”
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