A scratchy 1-0 World Cup qualifying win against Andorra in Barcelona last week was followed up by a friendly defeat to Senegal at the City Ground.
Tuchel, reflecting on the week, said: "Gareth (Southgate) and Lee (Carsley) tried it, to bring as many of these highly talented players together.
"I am trying now at the moment and still we feel we are lacking the enthusiasm and the joy consistently on the international level.
"I can just underline that the individual has to take a step back for the greater good. It's on us to find the right mixture, the right team, the right chemistry and the right connections in the team that they enjoy to play with each other. We haven't done this yet.
"The first camp was a step in the right direction, the second camp was a bit of a mixture. We come to September, October and November, where by nature it gets more competitive and more straightforward in selection and the tone because we enter a World Cup year."