Horak, who was unavailable for the Exiles game against London Wasps last week after flying to South Africa for personal reasons, replaces Ed Thrower, with the latter dropping out of the squad completely.
London Irish: 15 Michael Horak, 14 Paul Sackey, 13 Geoff Appleford, 12 Nils Mordt, 11 Justin Bishop, 10 Mark Mapletoft, 9 Darren Edwards, 8 Chris Sheasby, 7 Kieron Dawson, 6 Phil Murphy, 5 Bob Casey, 4 Ryan Strudwick (captain), 3 Rob Hardwick, 2 Naka Drotske, 1 Neal Hatley.Replacements: 16 Doug Wheatley, 17 Adrian Flavin, 18. Kieran Roche, 19 Declan Danaher, 20 Rob Hoadley, 21 Kevin Barrett, 22 Barry Everitt.
Kick-off: 15.00 BST
