I think he changes our game. City in the past have pressed us back to Alisson and win back possession from his clearance. With Kelleher he is so calm on the ball that City were not able to gain back and dominate possession like they used to in greater quantities.
I think we need to have a conversation at the least about the future #1, against pressing teams he gives us an extra footballer. His shot stopping is extremely good, and he might not have the presence of Alisson but I seriously in my mind feel we need to have him on the pitch especially against pressing teams.