Italian second row Marco Bortolami will skipper the side after overcoming a knee complaint picked up during Gloucester's 50-9 semi-final victory over Saracens last weekend.
The only change to the squad is the inclusion of Jake Boer, who returns to the bench after suffering ligament damage during his try-scoring performance against Bristol a fortnight ago, and replaces Adam Eustace.
"Leicester are an outstanding side, capable of switching to any game if they chose to," said Ryan. "We find ourselves talking about respect a lot but in this case Leicester are a side who deserve a massive amount because of their recent history.
"It is up to us to get our specifics right, of when we opt for our attacking choices and when we need to be more pragmatic.
"To me, reaching the final is a wonderful achievement for this side. They have consistently surprised me with the way they have rebounded from disappointments and I am thrilled for them because they have worked so hard this season. I firmly believe this side will keep improving, keep developing and keep maturing. If both teams find their game tomorrow, it will be a cracking contest."
Ryan's forward pack has a settled and experienced feel to it. Nick Wood will partner hooker Olivier Azam and tight-head prop Carlos Nieto in the front row. Bortolami will partner Alex Brown at lock, while Luke Narraway, a try scorer against Saracens last weekend, will retain his place at number eight alongside flankers Peter Buxton and Andy Hazell.
Gloucester have drawn one and won one against the Tigers this season and have not suffered defeat against the treble chasers since a 25-20 reverse at Welford Road in 2005.
In the backs, Peter Richards will make his final Gloucester appearance tomorrow before he joins London Irish and will partner Ryan Lamb at half-back.
In the centre, England duo Anthony Allen and James Simpson-Daniel will retain their partnership which means Mark Foster, Iain Balshaw and Willie Walker complete the back three.
The bench is equally experienced with Mefin Davies and Christian Califano the front row replacements. Will James will cover lock and Boer the back row.
In the backs, Ryan's options are scrum-half Rory Lawson, centre Jack Adams and full-back Jon Goodridge.
Gloucester (vs Tigers tomorrow, Twickenham, kick-off 2.30pm)
15 Willie Walker
14 Iain Balshaw
13 James Simpson-Daniel
12 Anthony Allen
11 Mark Foster
10 Ryan Lamb
9 Peter Richards
1 Nick Wood
2 Olivier Azam
3 Carlos Nieto
4 Marco Bortolami (captain)
5 Alex Brown
6 Peter Buxton
7 Andy Hazell
8 Luke Narraway
16 Mefin Davies
17 Christian Califano
18 Will James
19 Jake Boer
20 Rory Lawson
21 Jack Adams
22 Jon Goodridge