Captain Harry Kane said England must improve quickly if they are to contend for next year's World Cup after slumping to a 3-1 home friendly defeat by Senegal on Tuesday.
A first ever defeat against African opposition has put England boss Thomas Tuchel under pressure just four games into his reign.
After struggling past minnows Andorra 1-0 in World Cup qualifying on Saturday, Tuchel's 10 changes had little effect as Senegal ran out deserved winners in Nottingham thanks to goals from Ismaila Sarr, Habib Diarra and Cheikh Sabaly.
"Not good enough. We had moments, but with and without the ball things aren't clicking, we're not finding the right tempo," said Kane, who opened the scoring with his 73rd international goal.
"We've lost that aggressive nature that we had."
Former Chelsea, Bayern Munich and Paris Saint-Germain boss Tuchel was hired with the task of taking England one step further to major tournament glory after losing in the last two European Championship finals.
Kane believes his side is going through a transition period since Gareth Southgate's departure after Euro 2024, but said there is little time to get things right with the World Cup now just a year away.
"We're not going to panic but we know we need to be better," added the Bayern Munich striker.
"New ideas, there's new players coming into the team that don't have experience at international level. It's a mixture of things but no excuses.
"We need to find it quick, the World Cup is going to come around really fast so every camp is really important right now."
England are at least in pole position to qualify having won all three of their qualifiers to date against Albania, Latvia and Andorra.