Celtic manager Ange Postecoglou stressed the importance of their defensive approach after his side went five matches without conceding a goal.
Greg Taylor and Cameron Carter-Vickers returned to the back four on Sunday as Celtic beat Dundee United 2-0 at Tannadice.
Postecoglou said: “I think our whole defensive work since the break has been outstanding.
“Led from the front with Kyogo’s pressing, but with everyone really committed to being really aggressive with our defensive work.
“I think that is reflected, and it gives us the foundation to play our football. Obviously the back four is a big part of that, Joe (Hart) is a big part of that, but it is just collectively I think our defensive work has been really top notch.
“I don’t know if it gets overlooked but we certainly look at it that, for us, it is the foundation we build our football on.
“If we are working really hard defensively, collectively, and really organised and disciplined, it suffocates the opposition. It doesn’t give them time to breathe and allows us to wear teams down, break them down one way or another.
“That’s through everyone being committed to it. It is a very important part of our game. We wouldn’t be the attacking side we are and score the goals we do if we didn’t have the defensive framework to fall back on.
“It’s not easy to defend in our team. We are constantly pushing the line, but we want to be aggressive. It means a lot of one-on-one defending, one defending without cover.
“You need to embrace that as a defender and be willing to put yourself on the line.”