The 30-year-old Leeds-born hooker spent over a decade with the Warriors before his switch to the Dragons.
"It's going to be a bit of a weird one but I'm looking forward to seeing some familiar faces," said McIlorum, who signed a two-year contract with the French club in January.
"It will be more strange going back to Wigan, to the DW Stadium, and sitting in the away changing rooms.
"I moved over straight from school when I was 16 so I've been in Wigan pretty much all my adult life. It's a place that I call home and my girlfriend is from there and a lot of very close friends are there.
"But it's a professional sport and these things happen."
🇫🇷 Steve McNamara a dévoilé le groupe pour la réception de Wigan ce samedihttps://t.co/a8SmjZAmqT
— Dragons Catalans (@DragonsOfficiel) April 5, 2018
🇬🇧 Steve McNamara has named the squad for the Saturday game against @WiganWarriorsRLhttps://t.co/W2nb3eiDLp pic.twitter.com/2Xg9oHaq9w
McIlorum, who was still under contract with the Warriors, caught the eye of Canberra during an impressive 2017 World Cup campaign in Australia with Ireland, but the Catalans came up with a more suitable offer and - after mutually agreeing the move with Wigan chairman Ian Lenagan - he says he is happy with the outcome.
"I'm absolutely loving the lifestyle and obviously the weather is a lot nicer, so I'm enjoying that," he said.
Catalans are bottom of the table after just two wins from their opening nine fixtures, but McIlorum is hoping their 27-6 win over Huddersfield Giants on Monday will kick-start their campaign.
"I'd say the word is frustrating, coming from Wigan and being quite successful," he added.
"We got off to a bad start and had injuries to both our half-backs, but hopefully that win on Monday will stand us in good stead and get a bit of confidence into the team because the squad is really good.
"We've got some good players, we just need to start playing as a team.
"I haven't seen any of Wigan's games but I expected them to have a good season this year.
"With the disappointing season last year I knew how hard Waney (Shaun Wane) would have been training them and I knew how hungry the players will have been to make amends.
"I'm expecting a really tough game on Saturday."
👥 SQUAD NEWS
— Wigan Warriors ðŸ’âšªï¸ (@WiganWarriorsRL) April 5, 2018
Warriors name 19-man squad for trip to Perpignan to face @DragonsOfficiel on Saturday.
Tautai and O'Loughlin back in squad, Powell available following illness.
âž¡ï¸ https://t.co/2A1etX4Xeq pic.twitter.com/ZjgGNMerMB
Elsewhere on Saturday, Warrington Wolves will seek a fifth straight win when they go to Salford Red Devils and Widnes Vikings are looking for a first away victory of the season when they visit Hull KR.
