Gillespie, who hands over the Deramore Park coaching reins to retired Ulster skipper Andy Ward next month, has included Ulster hooker Rory Best on his replacements bench for Saturday's decider against Shannon.
Gillespie though, has resisted the chance of calling up the Belfast side's contracted stars Kevin Maggs and Tommy Bowe to his backline as he keeps faith with the side that edged past Garryowen 15-8 last weekend.
"We've kept faith with the side that got us through the semi and it's just reward that they have retained their places," said the former North of Ireland club member.
"We can beat Shannon if we play to our ability, but certainly they are a very good side with lots of experience, especially having been in the AIB play-off final on three previous occasions."
"We'll draw on the experience of that win. It set us up for the rest of the season and gave the guys a lot of confidence know they could get the better of Shannon," admitted Gillespie.
"We will have to be well-prepared for Shannon. They can play a tight game, have a good pack and a good front row and will be hard to beat and looking for a revenge of sorts," he added.
Gillespie has a potential match-winning halfback pairing in 23-year-old Ian Humphreys, younger brother of Ireland international fly-half David, and 1999 Heineken Cup-winning scrum-half Andy Matchett, who turns 36 later this month.
Kiwi-born and Edinburgh-bound Ulster lock Matt Mustchin is also at the coal face of a strong 'Quins pack.