The pair have won the best band title twice in a row, as the Strutts, despite changing the line-up from its original five-piece format last year.
The Mount Aspiring College musicians have been joined by drummer Alastair Mawhinney this year, who replaces Bink Bowler.
With the third line-up change in as many years, the three-piece has opted for a new band name - the Slur-Tones.
Tomorrow night's performance at the Lake Wanaka Centre would be Alistair's first time playing in the competition, but Fabian and Yannick could almost be considered Rockquest veterans, as they each appear for the fourth time.
The pair played in different bands before founding the Strutts in 2006 which made it through to the final 12 last year.
Eighteen bands will compete for the Southern Lakes regional Rockquest title, from which two finalists will advance to the national finals.
The concert starts at 8pm tomorrow at the Lake Wanaka Centre.
