The Tractor Boys won 3-0 against League One Bristol Rovers at Portman Road in the FA Cup.
After picking a strong team, McKenna saw Kalvin Phillips, Jack Clarke and Jack Taylor net goals in a dominant win.
“I think it was a really good performance, individually and collectively,” McKenna said post-game.
“The first half was a really good game and I thought we played really well.
“We scored good goals, could have scored more, gave very little away and managed the game well in the second half. So through to the next round and a good day for us.
“I think that’s a really good sign for the group.
“We’ve had that for the last few years on different occasions where in cup competitions we’ve been able to change the whole team and, it hasn’t always worked out, but very often we’ve been able to produce very cohesive performances still and have players ready to come into the team and be match ready and fully understanding their roles.
“When you can make changes like we did today and look as cohesive as we did in the first half especially, I think that’s a big, big positive for the group, and especially when you consider quite a few of that group have been here for a few years but there’s also quite a few of that group who have been here for a few months and you can see are starting to settle in, and Ben Godfrey’s only been here for a few days.
“In those circumstances, to look as cohesive as we did on and off the ball, I think that’s a good sign for the direction that the group’s travelling in.”