Prop Boris Stankovich also makes his return from an injury absence and lines up alongside Mefin Davies and Martin Castrogiovanni in an experienced front row.
Ian Humphreys and Christophe Laussucq form the half-back combination, while Seru Rabeni returns to the backline after sitting out last Sunday’s trip to Sale Sharks.
Deacon is joined in the second row by Marco Wentzel, while Brett Deacon and Tom Croft are joined by Jordan Crane in the back row.
Aaron Mauger and Dan Hipkiss are named at centre, with Rabeni, Johne Murphy and Sam Vesty completing the backline.
“Louis Deacon led the team well at the start of the season and it is good to have him and Boris back in the squad,” said Tigers head coach Marcelo Loffreda.
“We are making some changes but we have a lot of confidence in our squad and we trust the players that will play.
“It is going to be a very hard game. London Irish have a good team, they are performing very well.”
Tigers lost 20-14 in their last league outing, at Sale Sharks last Sunday, but Loffreda says they have learned some of the lessons from that game.
“It is very close between winning and losing,” he said. “At Sale, we didn’t score when we had to score and we made a lot of errors. I think we have to work very hard on our concentration.”
Alesana Tuilagi is still sidelined with a groin injury, while Lewis Moody (ankle), Marcos Ayerza (dead leg), James Hamilton (ankle), Geordan Murphy (hip) and Luke Abraham (illness) are unavailable for selection this weekend.
With Leicester City also at home and kicking-off at 3pm, it is recommended that all supporters allow extra travelling time to and from Welford Road on Saturday.
Tigers team (v London Irish, Saturday 2.45pm at Welford Road)
15 Sam Vesty
14 Johne Murphy
13 Dan Hipkiss
12 Aaron Mauger
11 Seru Rabeni
10 Ian Humphreys
9 Christophe Laussucq
1 Boris Stankovich
2 Mefin Davies
3 Martin Castrogiovanni
4 Louis Deacon (c)
5 Marco Wentzel
6 Brett Deacon
7 Tom Croft
8 Jordan Crane
Replacements
16 Benjamin Kayser
17 Julian White
18 Ben Kay
19 Ben Herring
20 Frank Murphy
21 Ollie Smith
22 Tom Varndell