Sven-Goran Eriksson insists he has not blundered by taking too few strikers to the World Cup after England laboured to an opening 1-0 win against Paraguay.
Captain David Beckham gives England's victory over Paraguay the thumbs-up
Having opted not to bring a fifth striker to Germany, the coach withdrew Michael Owen after 55 minutes which sparked a poor second-half performance.
Eriksson said: "I changed it because we wanted some fresh legs but Michael did well and I'm sure he will get better.
"I don't regret what I did picking the team and it was vital to get this win."
Eriksson said that the decision to replace Owen with Stewart Downing, was purely tactical.
He added: "I thought we were finding it difficult to keep the ball so I tried to have a player who could link the ball up a little and Joe Cole did very well in that role."
But the Swede refused to concede that the substitution caused his side's performance to fade.
"I think we lost rhythm, I think we started the second half poorly but I think it got better at the end," he said.
I'm sure we will play better and better every game. It is a good start
England coach Sven-Goran Eriksson
England needed a third-minute Carlos Gamarra own goal to seal the victory and Eriksson told BBC Sport: "I'm pleased that we got the victory.
"We found it difficult to keep the ball in the second half. But we will get better in the next match and it was important to open with three points.
"Four years ago we got a draw in the first match and last time (Euro 2004) lost against France. To win the World Cup we will have to play better football but we will.
"We will have to play 90 minutes like the first 25 but I'm sure we will play better and better every game. It is a good start."
Eriksson also explained his decision to bring on Owen Hargreaves in the second half.
"He is very important in many ways. He wins tackles, wins the ball, plays it simple and gives more freedom to Lampard and Gerrard. He is very useful player to have."
England captain David Beckham blamed England's poor second half show on the heat.
"You don't realise how hot it was out there," he said.
You don't realise how hot it was out there
England captain David Beckham
"We were good at times but we gave away the ball too much. But it was hot and we got what we wanted. That was a good start and we have the three points.
"The performance could be better but we will work on that. We set out to get the three points and we did that.
"But we were exhausted. We can put it down to that because we are usually strong and our fitness levels are high.
"This was a three o'clock kick-off and it was 28 or 29 degrees out there," he said.
Beckham's team-mate, Frank Lampard, stressed the result was more important than the performance.
"To get three points in our first game is the important thing," said the Chelsea midfielder.
"We know we can do a bit better but we've got a bit of time to work on things - and we will get better.
"Once the dust settles we'll see what an important result this is.
"We started really well with great intentions, moved the ball really well and got a goal but I think we were more upset by the fact we didn't add another.
"But we defended well and that's a big plus for us today."
Steven Gerrard asked about Owen's withdrawal in the second half, added: "Michael worked very hard for an hour.
"He is fighting for that match fitness and I'm sure it will come very soon."