The Irons were thrashed 5-0 on Sunday.
Zouma told the club's website: “Today was a really bad day.
“It was a bad day at the office and there was nothing today. Our performance was really bad. Losing five-nil, there is nothing to say, just sorry to the fans who came to support us. It's a day to forget and we have to bounce back really quick.
“I think they were better than us everywhere on the pitch. They were just better than us, they ran more than us, they wanted to win more than us and physically they were maybe sharper than us.
“I think we couldn't deal with them today. Physically we were nowhere near the levels and even mentally I would say we were nowhere near the levels, me first, and like I say it was a day to forget.
“We have to take responsibility and we take it and we stay as a team and we have to bounce back as quick as possible."