The Three Lions crashed out of the tournament at the group stage, but the 31-year-old has insisted that the younger members of the side will have reaped the benefits of playing against top-quality teams.
Jagielka told reporters: "It's all part of the learning curve for the young lads - time-wasting and things like that are things we don't do enough of.
"They are things maybe we could look into to be that bit more professional.
"We have got some fantastic young lads and they are getting experience playing on the big stage like this so I wouldn't call it an absolute nightmare or a waste of time."
England take on Costa Rica in their final Group D game on Tuesday.