Ben Godfrey arrived on loan from Atalanta, while Jaden Philogene joined permanently for £20M from Aston Villa.
Julio Enciso was loaned from Brighton, and goalkeeper Alex Palmer was a deadline-day addition from West Brom for an initial £2M.
“They’re settling in well,” McKenna told reporters.
“Ben Godfrey was the first in, so Ben’s been here a few weeks more and has been around the English game and the Premier League and this end of the Premier League a little bit more, so a fairly easier introduction for him from a social point of view.
“Of course, from a football point of view, we know he’s arrived with very little game time, so he’s had a couple of games in the cup now and a big challenge against Man City. But the couple of games in the cup will stand him in good stead.
“Julio’s settling in well, that’s probably a more challenging integration in terms of a young player from another country not speaking in his first language. For Ipswich Town alone for a football club, certainly in my time, the first non-native English speaker that we’ve had.
“So that’s a really exciting challenge for us as staff, as a group of players as well to integrate Julio in, to make him feel welcome, to help him understand where the group’s at and the goals of the group and the needs of the group, and also for the group to understand how we can get the best out of him.
“That’s been really exciting and everyone’s enjoyed having him here and he’s settled in really well and I think performed really well against Southampton. Now it’s just about working to get the very best out of him.
“Alex came in last week and settled in straight away. He knows some of the players already, a similar background to many of our players, so that’s not a hard adjustment.
“And Jaden Philogene has settled in well. He knows Liam (Delap), he knows Omari (Hutchinson), he knows Greavesy (Jacob Greaves) and similarly, he’s settled in well.
“Socially he’s a likeable lad, he’s actually a bubblier lad that we knew, he’s a good character around the place.
“But again, he’s a young player who is coming in having not played much football this season and certainly not having played Premier League football, so we need to find the balance of trying to get the best out of him straight away and trying to put the demands of our team on him straight away.
“But also working with a level of understanding that he’s not played much football and integrating him into the Premier League and into a new group from where he’s been is a challenge.
“And we’ve got to stick right behind him for that because we believe he’s a talented player and he’ll be a good player for the football club. I think they’ve all fitted into the group well.”