Spencer Downey has already helped to arrange moves for Paul Dummet and Conor Newton to the Paisley club as part of an affiliation agreement with the Geordies and says England Under-19 cap Campbell could be next.
The 18-year-old - who turns 19 on New Year's Day - was close to agreeing a deal with the Buddies during the summer but moved to Carlisle on a short-term switch instead.
But now Downey says Saints boss Danny Lennon could finally get his man.
He said: "We're hoping to have that one tied up for January 1 and get Adam up there for the match with Kilmarnock the day after.
"Danny thinks he is fantastic. He's wanted Adam for a while and probably should have gone up there in August but it didn't work out that way.
"Newcastle value what St Mirren have done for Paul and Conor and believe sending Adam up there would be good for him.
"He's a live-wire striker and will bring so much to that team. Steven Thompson will love him. He has so much energy and is rapid. He has a good shot off of both feet and will score goals."
Campbell is highly rated by United manager Alan Pardew and made three Premier League appearances last season and another two in Europa League ties - but has yet to feature for Newcastle this term.
Meanwhile, Downey is also working on a deal that will see Newton's own loan stay extended until the end of the season.
The 22-year-old first joined Saints last January as he linked up with best friend Dummett - now back playing for the Magpies first-team.
The duo helped the Scottish Premiership side to the League Cup, with Newton scoring in the 3-2 win over Hearts in the final at Hampden.
St Mirren chief executive Brian Caldwell hopes to have the paperwork "concluded soon rather than later".
However, Downey - who represents the player - admits there is competition from clubs south of the border.
He said: "Because of how well Conor is doing right now he is attracting interest from clubs in the Championship.
"But he wants to stay where he is. Newcastle would like him to stay because he's progressing week in, week out.
"However, a lot of people are watching the SPL because it's a great breeding ground.
"But the question remains that with Conor doing so well, do we leave him where he is, or allow him to move on to a club in the Championship where he may have to settle in all over again?
"Both Danny Lennon and his assistant Tommy Craig are both clear when they say he is good enough for the Championship. He has good energy and skill."