The corridors, treatment rooms and gymnasiums of St George's Park bear quotes from global icons and sporting greats from Martin Luther King to Muhammad Ali. The one that has caught Wayne Rooney's eye is actually an observation from Ian Thorpe, emblazoned on the wall behind one of the hydrotherapy pools. "Losing is not coming second," it reads. "It's getting out of the water knowing you could have done better."

The Manchester United striker claimed to be unsure why that particular quote had "stuck in my mind", though perhaps on some level it merely struck a chord. Rooney is adamant he has always strived to perform at his best when England called, and has "given everything" for the cause. But there have still been times, most obviously at recent major tournaments, where his impact has been more spluttering than spectacular and he has departed prematurely to be unnerved by suggestions he has failed to do himself justice.

The anticlimactic exits feel familiar: there was the sending-off against Portugal in 2006, his grumbling mood and anaemic form in South Africa four years later, and the ring-rusty showing in a tournament wrecked by suspension in Ukraine this summer. Rooney is considered a talisman with the current England team, a player to whom team-mates look for inspiration, and yet the watching world still awaits evidence of his best. "I'd have liked to have played better for England but, for whatever reason, it hasn't happened," he said. "I'd like to know why, but I can hold my head up high and say I've always worked hard, given everything and will continue to do that.

"Sometimes it happens where you don't play well, but you have tried. It just happens. I always feel I have given everything, whether I have played well or badly. But, looking back, I know I can do better. But I wouldn't let the previous tournament distract me going forward. It's still a great honour to play for my country and I know I haven't played at my best but, being honest, as a team we can do better. I am not going to win a tournament on my own. We need the whole team to perform. But I can see we are heading in the right direction. I feel we are working well with a lot of younger players in the squad, and there is a different feel and way of playing when we are on the training pitch. It is a case of us moving forward."

The criticisms in the summer dated from his petulant kick at the Montenegro defender Miodrag Dzudovic back in qualifying, a misdemeanour that cost him participation in the first two games of Euro 2012. The fact he had spent time in Las Vegas in the buildup to the tournament also prompted some raised eyebrows, given that his fitness – albeit in terms of match sharpness – was exposed at the finals. "I can understand and see where people were coming from," he conceded when asked if such criticism had been fair. "Obviously I went out one night and that was seen, but I wasn't in Vegas going out every night drinking and partying.

"I couldn't train anyway. That is why I had the extra time off. I had to have something done to my toe – there was no treatment I could have had on that – and going there was just a way to relax before I came into training. But obviously I can understand, looking back, why the fans and some people weren't happy."

The scrutiny is never far away. Now at 26, and as San Marino quiver in their boots ahead of their trip to Wembley on Friday, Rooney feels more senior than ever. Steven Gerrard is suspended, John Terry retired, Ashley Cole potentially rested and Frank Lampard doubtful with a knee complaint. The youngsters will need an experienced focal point around which to buzz and the United forward is the obvious candidate.

"There are younger players in the squad and I always try to speak to them and offer advice," he added. "I always remember Sir Alex Ferguson saying what a big help [Eric] Cantona was to all those younger players at United. It is something I can look at and try to do for England with all these younger players. Hopefully I can bring the best out of them and they can bring the best out of me as well.

"I understand all the scrutiny and I have no problem with it. Hopefully, in the near future, we will be coming out of a tournament and you will all be praising me because we have won a trophy. That would be great for everyone." St George's Park is very much about looking forward. Rooney is eagerly doing just that.