Winger Marcus Maddison will complete a temporary switch to the Perth club on Thursday night, following midfielder Medhi Abeid in swapping Tyneside for Tayside.
Abeid penned a six-month loan move earlier on Thursday and now 19-year-old Maddison will do the same.
However, Press Association Sport understands the player will miss Saturday's William Hill Scottish Cup clash with St Mirren in Paisley - where he would have come up against Magpies team-mates Paul Dummett and Conor Newton.
Instead, the player will link up with Perth boss Steve Lomas and his squad on Monday.
Maddison's agent Spencer Downey has told St Johnstone fans they can expect a treat once the player is let loose on the Clydesdale Bank Premier League.
He said: "Marcus is tricky winger who plays down the left. This lad has got some set of skills and I think he will do brilliantly for St Johnstone.
"We're hoping the deal will be done tonight although he won't go up to Scotland until Monday, when he will train with the team for the first time."
- Sports & Recreation