Sam Allardyce has attributed England’s below par performance in Sunday’s World Cup qualifier against Slovakia on the humiliating defeat to Iceland at Euro 2016.

In the wake of the 1-0 win in Trvrna, Allardyce acknowledged that players’ mood changed on the morning of the match – a legacy, he said, of their round of 16 exit to Iceland.

“I think they were probably a bit nervous,” Allardyce said. “I saw a little nervous tension. It [Iceland] is bound to be in the back of their mind, isn’t it? They had a holiday, a pre-season, started the season with their clubs and then it comes to the first England game after Iceland and maybe there was nervous tension.

“It was too negative in the first 45 minutes. I think it was possession for possession’s sake rather than trying to break the opposition down. That was maybe sub-conscious, players thinking: ‘I don’t want to be the one who gives that ball away.’ I could see that: ‘What if I make that pass? Oh, I don’t know …’ But we have to be brave.

“I haven’t asked what their biggest fear is because I didn’t want to talk about fear. I wanted to be positive and tell them what the future is. The only thing I mentioned about the past was to learn from it and the only thing I said was don’t feel like that again next time around.”

The Football Association is no longer using Steve Peters, the Liverpool club psychiatrist brought in by Allardyce’s predecessor, Roy Hodgson, and has turned to the sports management company set up by the Olympic gold-medallist swimmer Adrian Moorhouse.

“It is different in terms of Steve Peters,” Allardyce said. “This is a company with many facets in their locker. We will use them on a consistent basis to help the players build resilience so they are able to cope with pressure better. Even though they already deal with a lot of pressure, on an international stage it’s a different type of pressure and they are very young. As a squad we are really young and as human beings, when we get criticised, we hurt – we really do.”

England 1 Iceland 2

Goalkeeper Joe Hart and two others player lie on the pitch at the end of the Euro 2016 round of 16 match between England and Iceland, at the Allianz Riviera stadium in Nice.

The psychological affects of that embarrassing defeat to Iceland continue to linger – a fact acknowledged by midfielder Eric Dier.

“There is a long way to go until the scars have been healed but it is a start,” the Tottenham midfielder said, after the victory in Slovakia. “All we can do is win against whoever we have in front of us but I think there is a long way to go before we repay everyone for what happened in the Euros. And for ourselves as well because we were the most unhappy of everyone and there is a long way to go until we are happy again.”

Much of the post-match debate centred on the performance of captain Wayne Rooney, a player Allardyce said was entitled to a free role due to his years of service as an England international. However, the new manager concededed that even he was surprised by how deep the Manchester United forward played against Slovakia.

“He’s not to forget we want him to score goals” – but it was clear that special rules applied to England’s most capped outfield player.

“I am using his experience to its maximum on the field, said Allardyce. “He has had it at Manchester United, under many different managers, playing down the right, the left, centre-forward, in behind, centre midfield. Mine and Wayne’s relationship, as we grow, will always be to promote him wherever he plays.”