The Frenchman featured in midfield in the Capital One Cup final win over Tottenham in March and the 1-0 victory at West Ham and last Sunday was assigned a similar role alongside Nemanja Matic against Louis van Gaal’s much-improved side.
Although United dominated possession, Jose Mourinho’s men secured the spoils thanks to Eden Hazard’s first-half winner and the manager was delighted with the success of his tactics.
Mourinho said: “Control their direct football to Marouane Fellaini and control the wingers from making crosses on the inside foot.
“Wait for a mistake and score a goal. We were able to make their important players disappear. Nobody saw them. They were in our pockets.”
Discussing the instructions on Monday, handed down last weekend, Zouma told Chelsea’s website: “I had to stay with Fellaini because we knew he is on fire at the moment.
“He has scored a lot of goals so I had to keep an eye on him, and I think I did it well. I had to be physical with him and stay close to him.
“The game was very difficult. The most important thing was that we had one chance and we scored. We defended very well. Manchester United didn’t have many chances to score. We stayed compact.”
Speaking immediately after the victory at Stamford Bridge, Mourinho saluted the efforts of the 20-year-old Frenchman and said: “I told Zouma I want the game to be 10 against 10, I didn’t want the game to be 11 against 11.
“During the week we were working for that and the game was 10 against 10. See the jobs he is doing for us, as a central defender playing against [Manchester City’s Sergio] Aguero, as a central defender playing against [Liverpool’s Raheem] Sterling.
“He played as the holding midfield player against Tottenham in a system with only one holding midfield player.
“Against Man United he played to stop Fellaini from playing in the box. He is doing amazing jobs for us. He is mentally very, very strong, too. Not just physically, mentally he is very strong.
“He’s learned a lot from a tactical point of view since his arrival. So we can imagine with him being aged 20, Chelsea has 10 years of Zouma.”
Watch Arsenal v Chelsea, live on Sky Sports 1 on Sunday, kick-off 4pm