London - Sunderland manager Dick Advocaat feared club supporters would walk out on his side with the Black Cats 4-0 down before halftime in the third round of the League Cup against Manchester City.
In March, a large number of supporters walked out when the Sunderland were 4-0 down to Aston Villa in Gus Poyet's final game in charge of the club.
"I was a little bit scared to be honest and thought hopefully the fans will stay -- and they did," Advocaat told BBC of Tuesday's 4-1 loss.
"I said we cannot go on this way because City will get double figures," the former Netherlands manager added.
Sunderland conceded their first goal within nine minutes when City's Sergio Aguero converted a penalty after Patrick van Aanholt had brought down Jesus Navas in the box.
By the 36th minute, Sunderland were down 4-0 thanks to goals from Kevin De Bruyne and Raheem Sterling, and Vito Mannone's own goal.
The Black Cats scored a consolation goal late in the second half when Ola Toivonen found the back of the net on the 83th minute.
Advocaat admitted the scoreline could have been even more embarrassing.
"We gave three goals away and even then they could have made it four, five or six nil," the 67-year-old Dutch said.
"At half-time I told the players, 'now you have to fight for each other and work for each other. Otherwise we make a fool of ourselves.'" he added.