Marcos Ayerza and Tom Youngs return to the Leicester Tigers front row for Saturday's Pool 3 climax against Ulster in Belfast.Argentina prop Ayerza and England international hooker Youngs were both among the replacements for the Round 5 win over the Scarlets last weekend but they swap places for this match with Michele Rizzo and Leonardo Ghiraldini.   Graham Kitchener, who is included in the England squad ahead of the RBS 6 Nations, also returns to the starting line-up as a replacement for Brad Thorn who was an early withdrawal in the win over Scarlets with a calf injury.   The only other change to the matchday 23 from last Friday sees the return from injury of Niall Morris, who is included on the bench.   Kick-off at the Kingspan Stadium in Belfast is a 5.30pm on Saturday. There is live coverage on Sky Sports, or follow the Tigers’ social media updates on Facebook and Twitter. If you are travelling to the game, you can also keep in touch and share your photos via the Tigers social media outlets.   Leicester Tigers (v Ulster Rugby, away, Saturday 5.30pm) 15 Mathew Tait 14 Adam Thompstone 13 Vereniki Goneva 12 Seremaia Bai 11 Miles Benjamin 10 Freddie Burns 9 Ben Youngs (c) 1 Marcos Ayerza 2 Tom Youngs 3 Logovi’i Mulipola 4 Graham Kitchener 5 Geoff Parling 6 Tom Croft 7 Julian Salvi 8 Jordan Crane   Replacements 16 Leonardo Ghiraldini 17 Michele Rizzo 18 Fraser Balmain 19 Sebastian De Chaves 20 Robert Barbieri 21 Sam Harrison 22 Owen Williams 23 Niall Morris   Ulster Rugby: 15 Jared Payne, 14 Tommy Bowe, 13 Darren Cave, 12 Luke Marshall, 11 Craig Gilroy, 10 Ian Humphreys, 9 Ruan Pienaar; 1 Callum Black, 2 Rory Best (c), 3 Wiehahn Herbst, 4 Alan O'Connor, 5 Franco Van Der Merwe, 6 Iain Henderson, 7 Mike McComish, 8 Roger Wilson Replacements: 16 Rob Herring, 17 Andy Warwick, 18 Bronson Ross, 19 Lewis Stevenson, 20 Clive Ross, 21 Neil McComb, 22 Paul Marshall, 23 Michael Allen