Gareth Southgate understood why fans booed his side after a dismal defeat to Iceland that the England manager hopes will "really focus the mind" heading into Euro 2024.

An expectant Wembley crowd let their frustrations known after an alarmingly poor performance in their last warm-up friendly against a side that will not even be at the finals in Germany.

Southgate's side were toothless in attack and porous at the back, with Jon Dagur Thorsteinsson's fine early finish securing Iceland another memorable win against England.

In 2016 that shock result ended their European Championship hopes, whereas the manager hopes Friday's 1-0 loss can act as a catalyst to continental glory.

"You'd like a good performance, a crowd that's been entertained and to be leaving on a high," Southgate said after the send-off friendly. "Clearly the performance wasn't at the level it needed to be.

"I think there are some very clear reasons for that, and it actually gives us a chance to really focus the mind because these last games going into tournaments can be a little bit scrappy like that in terms of focus, because players are worried about picking up an injury.

"The most disappointing part tonight was out of possession, we didn't press well. We were too stretched.

"We've actually in the last two or three games, in particular, been excellent at that, so that's the bit that we've really got to rectify.

"With the ball we could have been better, but we still created some very, very good chances.

"I think the players, or a lot of the players, needed the minutes – players that have been coming back from injury, players that have played a lot but have had a week's break and are out of that rhythm.

"Of course, at the end, where you ideally want the experience on the pitch to keep the calm and work your way back into the game, we were needing to take those players off to look after them.

"Look, a far from ideal night. I'm not going to dress up the disappointment about the performance.

"But, equally, we have to stay calm because we know what needs to be put right and we'll work on that between now and the game with Serbia."

Friday's friendly was supposed help build a feel-good factor heading into Euros, with the Group C opener against Serbia looming large on June 16.

Instead, it ended with bored fans aiming paper planes at the pitch and those left inside Wembley at the final whistle booing.

"I completely understand," Southgate said of the supporters' reaction. "We didn't play well enough to keep them excited within the game.

"As I said, we had some very, very good chances that normally would be finished, which could have given a different complexion to the game, and, of course, would have affected the confidence of the opponent.

"But that might also have masked some flaws that were apparent tonight.

"From my perspective, I've learned a lot from the game, but no qualms with the supporters' reaction.

"To have the fans with you here obviously makes a massive difference, but you have to give them enough goalmouth action, you have to play well enough, press and win the ball with intensity to keep them with you during the game.

"Tonight we didn't do that, so we have to accept the reaction as it was."

But as poor as the night was for England, they at least appear to have avoided new injury issues.

John Stones went down awkwardly in the opening minute and was withdrawn at half-time, with fellow centre-back Marc Guehi playing on despite taking a blow to the head in the second half.

Southgate said: "Marc, fine, I think. John, we decided at half-time, no point in taking any chances, because we're obviously so close to the to the tournament, and he's a very important player for us."