Despite not being able to qualify for the cup's latter stages, Fowler has named a strong side for the trip to Ireland. Blues prop Campese Ma'afu starts at prop alongside Ethan Lewis and Ryan Harford in the front row.
In the backs, Joe Griffin again starts at full back with Shaun Powell on the wing and James Thomas at fly half.
Ulster will provide a real test though with all but one of their starting team containing players who have represented Ulster at senior level, with a further three on the bench.
The team is captained by Neil McComb, who has been in impressive form in his recent RaboDirect PRO12 outings.
Belfast Harlequins' half backs Michael Heaney and Stuart Olding earn starts with Niall O'Connor and Michael Allen forming a midfield partnership. Wingers Chris Cochrane and Ricky Andrew join Adam d'Arcy in the back three.
Cardiff: 15 Joe Griffin 14 Shaun Powell 13 Matt Smith 12 Darren Ryan 11 Tom Williams 10 James Thomas 9 Sion Hopkins, 1 Campese Ma'afu 2 Ethan Lewis 3 Ryan Harford 4 James Murphy 5 Matthew Screech 6 Reuben Tucker 7 Thomas Young 8 Dan Crimmins.
Replacements: Callum Lewis, Aaron Fowler, Alwyn Lee, Ellis Jenkins, Alex Walker, Richard Smith, Steve Cullen.
Ulster: 15 Adam D'Arcy 14 Ricky Andrew 13 Michael Allen 12 Niall O'Connor 11 Chris Cochrane 10 Stuart Olding 9 Michael Heaney, 1 Conor Carey 2 Niall Annett 3 Richard Lutton 4 James Simpson 5 Neil McComb (c) 6 Conor Joyce 7 Ali Birch 8 Mike McComish.
Replacements: Rob Herring, Adam Macklin, Alan O'Connor, Sean O'Connell, Blane McIlroy, Stuart McCloskey, Rory Scholes.