Italy international Castrogiovanni starts in place of the suspended Julian White in a team captained by full-back Geordan Murphy in the absence of the injured Martin Corry and Aaron Mauger.
International forwards Jordan Crane and Craig Newby return from injury to claim a place among the replacements.
Acting head coach Richard Cockerill said: “We’ve had a few of our injured players back this week which has given us some more options and all the guys who have been involved have been playing very well.
“We are down to the last eight in the major club rugby tournament in Europe and that means coming up against very good sides who are in good form. Bath are in that category and they play some good rugby.
“We have played them three times this season and they have been very tight encounters each time.
“We have prepared well and the players have been looking forward to it. I’m sure our supporters will provide a cracking atmosphere and I hope the game lives up to such a massive occasion.”
As well as Corry and Mauger, Tigers are without Richard Blaze (foot), Brett Deacon (foot), Ben Herring (head), Derick Hougaard (back), Benjamin Kayser (neck), Lewis Moody (ankle), Matt Smith (ankle) and Marco Wentzel (knee) due to injury.
Tickets remain on sale for Saturday’s game, which is a 6pm kick-off at the Walkers Stadium. Contact the Tigers ticket office on 08701 28 34 30 or call in at Welford Road. The ticket office at Welford Road is open until 5pm on Good Friday and from 9am to 5.30pm on Saturday.
Leicester Tigers (v Bath Rugby, Walkers Stadium, Saturday 6pm)
15 Geordan Murphy (captain)
14 Scott Hamilton
13 Dan Hipkiss
12 Sam Vesty
11 Alesana Tuilagi
10 Toby Flood
9 Harry Ellis
1 Marcos Ayerza
2 George Chuter
3 Martin Castrogiovanni
4 Louis Deacon
5 Ben Kay
6 Tom Croft
7 Ben Woods
8 Ben Pienaar
Replacements
16 Mefin Davies
17 Dan Cole
18 Jordan Crane
19 Craig Newby
20 Julien Dupuy
21 Ayoola Erinle
22 Johne Murphy
