England will meet Slovakia in the round of 16 after an underwhelming group campaign.
Plymouth boss Rooney told BBC Sport: "The messages coming from the pitch are very different to the last two tournaments. There's definitely something wrong (with England). I think the positive thing about the last two games is that it can only get better. You're going to be playing better opponents, so you have to improve. And try to get a good win."
Rooney also insisted that Harry Kane and his teammates need to come clean about their style of play.
"For me, the players need to take responsibility too. The captain, Harry Kane, said he didn't know how to press (after the draw against Denmark). If I'm in that team and I go onto the pitch and I don't know how to press or how to play, it's a big concern and a bit worrying.
"And that's when you go to the England manager, you go to the coaches and say, 'Right, before you go on the pitch, every single player needs to know how to press'."