England manager Steve McClaren has called off a trip to the United States next week to look at coaching methods in American football's NFL after his team's Euro 2008 defeat by Croatia.

McClaren has faced widespread criticism of his tactics in Wednesday's 2-0 defeat in Zagreb, which followed another poor display in last weekend's 0-0 home draw with Macedonia.

The Football Association said in a letter to media editors that "the time is not right" for the five-day trip to Seattle and that McClaren will instead prepare for England's friendly on November 15 against the Netherlands in Amsterdam.

McClaren, who has five months until England's next Group E qualifier away to Israel in March, is due to arrange another friendly in February.

Although he believes the current squad is good enough to qualify for the 2008 finals in Austria and Switzerland, McClaren indicated that he is willing to make changes and that he is also keeping an eye on young players coming up through the ranks.

"There are players in the Under-21s knocking on the door, we will be looking at them very, very closely," McClaren was quoted as saying in the British media yesterday.

"We will use the two friendlies effectively and maybe our approach will be different in some respects."