Tigers include 14 players with first-team experience as they look to overcome a seven-point deficit against the side they defeated at this stage of the competition back in 2005.
Key's side lost the first leg 34-27 at Henley but will be hoping that a bumper Welford Road crowd can spur them on to a hat-trick of A League titles following successful campaigns in both of the last two seasons.
Johne Murphy and Ian Humphreys, who were recently selected in the Ireland A squad for this summer's Churchill Cup, take their places in an exciting-looking backline, with Matt Cornwell captaining Tigers from outside centre.
Ben Youngs, who became the youngest ever player to appear in a competitive first-team fixture for Tigers against Sale on Good Friday, joins Humphreys at half-back with older brother Tom earning the No.12 berth.
In the forwards, England Saxons players Tom Croft and Jordan Crane start alongside Luke Abraham, with Scottish international James Hamilton packing down alongside England U-19 cap Gregor Gillanders at lock.
In the front row, Michael Holford starts at prop against the side he joins next season, with Dave Young and academy hooker Greg Sammons also included.
Tonight's match kicks off at 7pm at Welford Road. Season ticket holders and members have already received vouchers entitling them to free entry. Admission for other supporters is just £5 for adults and £1 for children.
Can you help?
This evening's team includes a number of players who have come through the ranks at the Tigers Academy. The academy have now recruited a new crop of players, aged 16, who will join the club in the summer to begin their quest for success in the professional game. Several have homes away from Leicester and we need to find lodgings for them locally. The academy is now seeking interested households, who would be prepared to provide a room and meals for one or more of these players, for next season.
While in Leicester, the players will continue their academic education and attend the academy.
If you are interested in helping us in this way, we are very keen to hear from you, so please get in touch. There are two contacts at the academy at Oval Park who are standing by to provide more details: Mike Harrison our academy education and welfare officer and Teresa Chester, the academy administrator who can be contacted on (0116) 2171325.
Tigers Development XV (vs London Wasps, Welford Road, kick-off 7pm)
15 Johne Murphy
14 Matt Smith
13 Matt Cornwell (c)
12 Tom Youngs
11 Ollie Dodge
10 Ian Humphreys
9 Ben Youngs
1 Michael Holford
2 Greg Sammons
3 Dave Young
4 Gregor Gillanders
5 James Hamilton
6 Tom Croft
7 Luke Abraham
8 Jordan Crane
Replacements
16 Tom Collett
17 Dan Cole
18 Ian Nimmo
19 Ben Pienaar
20 Ben Herring
21Greig Tonks
22 Paul Burke