Hamilton takes his place on the wing after being rested for last weekend’s Guinness Premiership win over Bristol Rugby, while Ayerza comes into the front row, alongside George Chuter and Martin Castrogiovanni.
The Tigers have named six internationals on the bench, including Julian White, Harry Ellis and Aaron Mauger who makes his return to the matchday squad after injury.
Cardiff Blues coach David Young has made one change to the side to face the Tigers. There is one change from the 22 that defeated Toulouse in the quarter final and won the EDF Energy Cup in Twickenham a fortnight ago.
Richie Rees starts at scrum half instead of the injured Jason Spice, while Darren Allinson takes his place on the bench.
The Millennium Stadium are expecting a crowd of over 50,000 fans for the match and supporters can still purchase tickets for the big match on the day, which are available from the marquee near Gate 3 of the Millennium Stadium.
Blues: 15 Ben Blair 14 Leigh Halfpenny 13 Tom Shanklin 12 Jamie Roberts 11 Tom James 10 Nicky Robinson 9 Richie Rees 8 Xavier Rush 7 Martyn Williams 6 Maama Molitika 5 Paul Tito (c) 4 Bradley Davies 3 Tauf’au Filise 2 Gareth Williams 1 Gethin Jenkins
Substitutes: 16 John Yapp 17 T Rhys Thomas 18 Deiniol Jones 19 Andy Powell 20 Darren Allinson 21 Ceri Sweeney 22 Gareth Thomas
Leicester Tigers 15 Geordan Murphy (captain) 14 Scott Hamilton 13 Dan Hipkiss 12 Sam Vesty 11 Johne Murphy 10 Toby Flood 9 Julien Dupuy 1 Marcos Ayerza 2 George Chuter 3 Martin Castrogiovanni 4 Tom Croft 5 Ben Kay 6 Craig Newby 7 Ben Woods 8 Jordan Crane
Replacements: 16 Benjamin Kayser 17 Julian White 18 Marco Wentzel 19 Lewis Moody 20 Harry Ellis 21 Aaron Mauger 22 Matt Smith
