The Dubliners finished the regular season at the top of the table and have home advantage for Saturday's showpiece but Heaslip insists a second Magners League crown in three years will only come their way if they can improve on everything they have achieved so far this term.
"We have a huge test coming up next weekend against the Ospreys and it will be another massive battle up front," said Heaslip, who has been one of Europe's standout performers since returning from his first Lions adventure.
"They have an array of talent out wide so we will have to up our levels again next week.
"There's no sense of our season being complete even though we were pleased to beat Munster in the semi-final."
Leinster will go into Saturday's showpiece on the back of a jam-packed season with a run to the semi-finals of the Heineken Cup coming on the back of the 2009 Lions tour but Heaslip has dismissed any suggestion that fatigue will play a part at the weekend.
The powerful back-row star says departing head coach Michael Cheika has worked wonders with a rotation policy that has left the Leinster players feeling fresh right up until the very end of the year.
"The way the Leinster squad has been managed this year has kept guys fresh for every game and that has affected me positively, touch wood," added Heaslip, who played in all three Tests for Sir Ian McGeechan's elite last year.
"It's also down to Cheiks' ability to rotate the squad, the fitness coaches for keeping us fit and healthy, and everyone on the squad pushing each other because of the competition that's there."
Heaslip will be hoping that Saturday sees him pick up yet another trophy after he was voted Leinster's Player of the Year.
The 26-year-old followed in the footsteps of fellow Lion Gordon D'Arcy, Felipe Contepomi, Bernard Jackman and Rocky Elsom when he received the award in front of more than 350 guests at a dinner in the Irish capital.
Heaslip has played in 10 Magners League games and 18 fixtures overall this season, winning almost endless plaudits for his combative displays.
"It is a huge honour to receive this award. I don't think I've ever received an award of this stature before on an individual basis and I wouldn't like to take too much credit because I couldn't have achieved this without my team-mates and coaches.
"While it's humbling and I'm extremely grateful to receive this award, I hope that it won't be the last one for this season."