Campbell, 38, who made 73 senior appearances in an 11-year international career, is in no doubt what the problem is - the attitude of England youngsters stinks compared to their counterparts from other countries.
Ex-Arsenal star Campbell told the Daily Star: "I think with the Under-21s, and with football in general in England, the quality has gone down.
"Yes, there are some really good players coming up, but, on the whole, they think they're there already.
"There are a lot of other countries around the world with very good players on top of their game but continue to work hard.
"They might be playing for the first teams already but they don't lose it. They do not think they have made it already.
"You keep on learning, you have got to keep on striving and that is what I feel has gone from English football."