Doncaster have made forward Dany N'Guessan their sixth summer signing.
Shrewsbury have rejected an offer from Burnley for winger Josh Ginnelly.
Paul Dummett spent the whole of last season with the Buddies while Magpies team-mate Conor Newton followed the left-back north in January after an affiliation deal was struck between the clubs.
Both players played integral parts as the Paisley side secured their first major trophy in 26 years as they beat Hearts 3-2 in the Scottish Communities League Cup final.
Magpies boss Alan Pardew was impressed by the way Saints handled the pair - who were both rewarded with new one-year deals - and he has already promoted Dummett to his first-team squad for the coming season.
Now he is considering sending 18-year-old Campbell - reared by Wallsend Boys Club, the youth side that famously spotted a young Alan Shearer's potential - north for a similar spell in the Scottish Premiership in a bid to speed up his development.
St Mirren manager Danny Lennon held talks with Pardew after Tuesday night's 2-0 friendly win for Newcastle at St Mirren Park and said: "I had a chat with Alan after the game.
"I looked at their squad on Tuesday night and even when they were taking guys off they were replacing them with players who are top drawer.
"Conor Newton came on in the second half and he did very well for us last year and we now have a strong affiliation with Newcastle.
"Young Adam Campbell looked lively when he came on and he is a player we are more than aware of."