World Cup 2014: Roy Hodgson rallies to the defence of England players after Roy Keane blast

Manager insists Phil Jones and Chris Smalling have not let him down as Portugal training camp begins

Phil Jones and Chris Smalling during training at Vale Do Lobo (Getty Images)

Roy Hodgson has defended his players Phil Jones and Chris Smalling against the latest onslaught from Roy Keane, saying that he and his England squad will be impervious to criticism as they begin their preparations for the World Cup finals this week.

Hodgson and the Football Association opened up their training camp at Vale Do Lobo on the Algarve, with an inaugural training session designed, in part, to replicate something like the conditions the players will face when they come up against Italy in Manaus in their first game at the tournament on 14 June.

But it was Jones and Smalling whom the England manager defended after criticism from Keane, who recently offered withering verdicts on the Manchester United pair in his capacity as an ITV pundit. Keane said that having watched the two this season he considered they had "gone backwards" in their progress. He said of Jones: "Every time I see him, he is getting carried off. He's got to toughen up."

Jones, still nursing a shoulder injury, trained separately from the rest of the squad. The only other player outside the group was John Stones, one of the two stand-by players who have travelled with the squad, who twisted a knee earlier in the week. Jones is still on schedule to be fit by the time England travel to Miami a week on Sunday and Stones is there as his understudy.

Hodgson said: "I am very rarely taken aback by things people say and rarely moved or disturbed by it. I work on the simple basis that everyone has an opinion. If you are a TV pundit you are required to give your opinion and I don't expect everyone's opinions to fall in with mine. If you say to me, has it been a great year for Manchester United and have Phil Jones and Smalling starred? Of course they haven't because they have used so many players and their back line has changed virtually every week to week.

"But as far as I am concerned they are England players because they have been England players through my two years and any games in particular that Smalling has played he has certainly never let me down. I don't think he's ever let the nation down whether he's played centre-back or right-back."

The England manager's sessions this week have been carried out in conjunction with the FA's head of performance Dave Reddin, who has worked in the past on the staff for the England rugby team and Team GB at London 2012. Reddin has used sports scientists from Loughborough University to try to recreate hot conditions – chiefly by insisting the players wear more layers of clothing in training than they ordinarily would.

Hodgson said the tests would allow the sports scientists to measure how his players react to the discomfort of high temperatures. "They went through the session with sweat pads on and they are being analysed. It is part of our process which Dave and his team have formed, learning to be comfortable being uncomfortable.

"So we started off on the first day just with them wearing the extra gear for the warm-ups. Then we went to the warm-up and maybe through part of the passing exercises wearing it, then maybe even halfway through my session. But the interesting thing was when the word came to take their tracksuits off there weren't too many who kept them on. They were very quick to whip them off so it is obviously working."

Cesare Prandelli's Italy squad were photographed coming out of saunas at their base in Coverciano near Florence, perhaps with the same thing in mind. The England squad were introduced on Tuesday night to acclaimed psychiatrist Steve Peters, who has worked at Liverpool under Brendan Rodgers.

Hodgson said: "He [Peters] said, 'This is me, what I've done, my career, and this is what I might be capable of doing to help'. And the players were very attentive and listened. He is an entertaining man. He just tells you all the things he's done in life. It's quite amazing. I don't know how old he is but to do all the things he's done in life he must be about 150 at least."