The former Home and Away actor is already back filming at the Ramsay Street soap ahead of an on-screen return later this year.
Digital Spy understands that Troy will be back in Erinsborough for a few weeks. However, details of his comeback storyline are currently being kept tightly under wraps.
Neighbours fans previously saw Troy arrive on the street in mid-2011 for a seven-week guest role, stirring up trouble for his old flame Sonya Mitchell (Eve Morey).
Shortly after his debut, it emerged that Troy was Callum Jones's biological father - and dramatic scenes followed as he tried to claim a permanent position in the lives of Sonya and his son.
A Neighbours source told Digital Spy: "Sonya eventually sent Troy packing last year, so his return will certainly ruffle feathers in Erinsborough. But viewers will have to wait and see why he is back and what's in store for him this time around."
Brummer is best known for playing Shane Parrish on Home and Away in the '90s.
> Read more Neighbours spoilers and news