The Paisley side have an affiliation link with the Barclays Premier League club that has already seen Paul Dummett and Conor Newton move to St Mirren Park on loan.
England Under-19 forward Campbell is reported to be the next Magpies recruit under consideration for a stint in Scotland but Lennon says he remains unsure if the deal will go through.
Toon boss Alan Pardew has yet to confirm whether or not he sees the 18-year-old playing a part in his squad for the new season and Saints boss Lennon says he will wait until the matter is clarified.
Lennon said: "Adam is a player that Alan thinks very highly of. I hear that he is getting mentioned for other places too.
"The lad will want to put his stamp down and remain a Newcastle player. But with the quality competition that he will come up against in that squad, it will be difficult for him.
"The only (thing) that gives us that wee edge is the development that we have had a part in for the two other players we have had here on loan.
"Until it becomes very clear what Alan wants to do with him, it becomes very disrespectful to speak about Adam going out on loan."
Motherwell and St Johnstone are also rumoured to be interested in the player while there is competition from English clubs, too.
Lennon is not even sure if his club will head the queue in Scotland.
"I don't expect to grab any player just because they become available," he said.
"It has to be right for all three parties.
"Just because we have a good relationship with Newcastle, it does not guarantee us that he will come.
"Adam is a very good player and like all managers at this stage, we are actively looking to improve our squad.
"When Adam's name comes up then, yeah, we will get linked with him because of the relationship we have with his club, but there are many other good clubs out there that will be linked with him."