Luongo, Cameron Burgess and Axel Tuanzebe are all coming towards the end of their contracts.
Asked if he could confirm whether any of them would be playing their last games for the club in Sunday's season-finale against West Ham at Portman Road, McKenna replied: "With Cameron and Axel, conversations are still going on with the club that will probably run into the week or so.
"But Massimo's going to be moving on in the summer. I think it's only right that the supporters, and I'm sure they'll be really keen to do so, have an opportunity to give him the farewell that he deserves."
Luongo initially joined on trial in December 2023 having been released by Middlesbrough. He subsequently signed a short-term contract and played a key role in the Blues storming to automatic promotion and then, against the odds, securing a successive step up to the Premier League. The 32-year-old started the opening two league games of this campaign, but has found his chances limited since then.
"He's been an incredible player for the club. Probably, if you wanted to look up his points per game and win percentages, until this season in the Premier League, he might be the best free signing in football history!
"From him arriving in that January (2023), his win ratio over the next 18 months was something incredible.
"Working with him day to day, I can tell you that's not an accident.
"I have to say, I think from a football IQ point of view and a game feel point of view, and I've said this to him, I think he's the best player I've worked with. And I've worked with some really good players. His football brain is outstanding and he's a competitor.
"To be honest, I think he can do a really good job still. He's still in good condition. He's training really well.
"He's still got a real good chance to go and push on next year and be a big player for someone and hopefully play in the World Cup and all those things. So that's really what the decision is based around, to be honest.
"I think he deserves to go and start a lot of games next season and hopefully push on and be an important player as a starter and earn a spot in the Australian squad, hopefully if they can qualify for the World Cup.
"And for us, it's a position as a club where we need to try and invest in the future. Sam (Morsy) and Mass have done incredibly for the club. And, of course, Sammy is still going to be an important part of it next year.
"But we need to invest in those roles, in those positions, and add depth to that midfield unit to help us not just for next season, but also for the seasons ahead.
"So I think it's the right decision for all parties.
"I know the supporters will be keen to send Massimo off well and he'll be keen to hopefully play a part in a big performance."