Geordan is given an immediate chance in the full-back jersey and Castro named among the replacements, with Alex Moreno replacing Stankovich at loosehead prop.
"It is great to have Geordan and Castro back," said acting head coach Richard Cockerill who has guided the team to three straight wins. "I am sure they will both be given a fantastic welcome by the supporters. They are very popular guys and they are both quality players.
"All of the guys who have been here for the first three games have done a tremendous job and we obviously want to keep that momentum, but this is a tough, tough game. Gloucester have had a great start to the season."
Murphy only returned from Rugby World Cup duty in midweek but says he cannot wait to get started again in a Tigers shirt.
"I have been trying to get back up to speed with the guys and the moves, but we're getting there," said Geordan who earned his 50th cap for Ireland in the final warm-up fixture before the World Cup and scored a try in the final group game against Argentina.
"I am looking forward to the game. There is an excellent atmosphere around the club and the lads have been great.
"It is fantastic to come back to play at Welford Road, the new stand looks fantastic and I am sure that will only add to the atmosphere."
Johne Murphy, who has played at No.15 in the opening three wins over Bristol, Bath and London Wasps, moves to the wing, while Frank Murphy completes the Irish contingent as he returns at scrum-half.
Matt Cornwell earns his first start of the season at inside centre and Julian White returns at tighthead prop after injury kept him out of the win at Wasps.
Ayoola Erinle returns to the matchday 22 after injury and is named on the bench.
Leicester Tigers (vs Gloucester Rugby, Welford Road, Saturday 6pm)
15 Geordan Murphy
14 Johne Murphy
13 Ollie Smith
12 Matt Cornwell
11 Tom Varndell
10 Andy Goode
9 Frank Murphy
1 Alex Moreno
2 Benjamin Kayser
3 Julian White
4 Louis Deacon (c)
5 Marco Wentzel
6 Brett Deacon
7 Luke Abraham
8 Jordan Crane
16 Mefin Davies
17 Martin Castrogiovanni
18 Richard Blaze
19 Tom Croft
20 Ben Youngs
21 Paul Burke
22 Ayoola Erinle
Tickets are still available. Contact the Tigers ticket office, call 08701 28 34 30 or visit the ticket section of this website.