England striker Harry Kane says it is too early to judge his attacking partnership with Wayne Rooney and Jamie Vardy.
The trio played together in England's 1-0 win over Portugal on Thursday, their final friendly before Euro 2016.
Vardy and Kane, who scored 49 Premier League goals between them last season, often drifted towards the flanks with Rooney playing through the middle.
"The understanding isn't just going to happen overnight," Kane, 22, said.
"Of course we would have wanted a few more chances and a few more shots at goal, but it's something we are still working on, so there is no reason for anyone to get too downhearted."
Victory over Portugal at Wembley - courtesy of Chris Smalling's 86th-minute header - was England's third in a row following wins over Turkey and Australia.
Kane added: "It's a learning curve. These games were to prepare us for the Euros and I feel they have done that."
Leicester striker Vardy made eight passes and did not have a serious threat on goal at Wembley, while Tottenham's Kane was caught in the head by the boot of Portugal's Bruno Alves, who was sent off.
England face Russia in their opening Euro 2016 game in Marseille on 11 June.
Kane said Roy Hodgson's side have been working on "two or three different formations" in training.
"It's important that you have that versatility going into a tournament so that if things aren't going right for you then you can change it," Kane said.
"We will start working towards the Russia game after a few days off and we will see what works best."
Of Alves' wild challenge, Kane said: "I am happy I'm still here. I was lucky not to have a few stitches. I think he just caught me with the top of his boot rather than his studs so I got away with one."
|England's Euro 2016 Group B schedule|
|Fixture||Venue||Date & time||BBC coverage|
|v Russia||Marseilles||11 June, 20:00 BST||ITV, BBC Radio 5 live|
|v Wales||Lens||16 June, 14:00||BBC TV, BBC Radio 5 live|
|v Slovakia||Saint-Etienne||20 June, 20:00||ITV, BBC Radio 5 live|
|Live text commentary on every game on BBC Sport website|