Gareth Southgate admitted England were lacking fluency in the 1-0 win over Czech Republic on Tuesday.
The result sees the Three Lions finish top of Group D, setting up a last-16 clash with Portgual, France, Hungary or Germany.
Despite his side failing to hit top gear, Southgate is confident England will improve.
"I thought we started really well," Southgate told ITV. "We were stable with the ball. We worked on some things in training yesterday but credit to the players as they had to adjust.
"Without the ball we changed what we were doing because of the change in personnel. It is huge credit to the players that they were as stable without the ball as they were.
"The Czechs are a really good side. They use the ball well and are really tough to break down. There is more to come from us, definitely. We have not scored from a set play yet which I know people laughed at with us only scoring from them. They are crucial in big matches and we have to get those nailed. We are not fluent but we have moments where we look a good side.
"Different sorts of tests. All of our next opponents will be different games. There is a lot of good things we are doing. We are getting minutes for a lot of the players. Ninety minutes for Harry Maguire was important tonight. Jordan Henderson getting 45 minutes is a step forward. A lot of positives."
