The former Newcastle United man is unbeaten in his six games against the Black Cats as a manager, and is preparing to face the side again with Bristol Rovers this afternoon.
But he will face a Sunderland squad who, under Johnson, are in the midst of a fine run of form and are climbing closer to the top two.
And Barton says he has been impressed by the club’s form in recent weeks – but also reserved praise for former managers Phil Parkinson and Jack Ross, while saying it is ‘about time’ Sunderland ‘got their act together.’
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“Lee’s done a superb job in a short space of time,” he said, speaking to the Bristol Post.
“They really look like they’ve turned a corner and they’re building a team that can get promoted out of the division.
“They’ve been on the periphery of that. I thought Phil Parkinson was doing an OK job, maybe not as well as some people wanted it done.
“I thought Jack Ross did a good job. Good men who did good jobs.
“It looks like Lee’s finally getting a tune out of them, but let’s be honest, they shouldn’t be in this division. A club that size with a passionate fanbase should never be in the third tier of English football.
“It just shouldn’t happen, so it’s about time they got their act together.”