Andy Murray sees no reason he cannot still beat Novak Djokovic, Rafael Nadal and Roger Federer, the champions who have been part of his own history, as he continues a comeback that looked out of the question six months ago.

He is back where he feels most comfortable in the entire tennis landscape, the second week of Wimbledon – even if only in mixed doubles – and it has plainly whetted his appetite to drive on for a while yet at 32.

Although his return after an absence of two years is now restricted to playing alongside Serena Williams, Murray believes he can compete again at the highest level in singles, the arena where he won his three grand slam titles, two of them at Wimbledon.

“Why not?” he says, when asked whether he still felt he could beat the best of the past and the best of the future. “If someone can give me a reason why I shouldn’t be able to compete again then I would listen to it, but so far I haven’t really been given one.”

What separates Murray from the herd is his single-mindedness. Throughout his 14-year professional career he has defied the odds and all expert opinion. He has invariably found a way.

None of his serial physical blows seemed to have killed his love of the game, although he came perilously close to walking away after his hip pain kicked in brutally in the first round of the Australian Open in January. One final operation saved his career.

It could hardly have been clearer from his demeanour on Centre Court on Saturday evening, when he and Williams laughed and smiled their way through an easy opening match, that he is convinced he made the right decision in carrying on.

The next challenge is to break out from the relatively undemanding world of doubles, in the men’s and mixed, to test himself in singles again. That could happen in Cincinnati in September as a dress rehearsal for a full return to the heat of competition at the US Open, where he won his first slam title seven years ago.

Much has happened since 2012 across the Tour as the rivals he grew up with have won their own struggles against injury and the ravages of time but Murray insists he can work his way back into that picture. “I know how bad I felt in Australia and how bad I felt the last year that I played singles here, and I feel better now than I did then,” he says.

His last singles appearance at Wimbledon, when he hobbled through five sets against Sam Querrey in 2017, mirrored the trauma of the Roberto Bautista Agut match in Melbourne but, as far as Murray is concerned, those experiences have been parked in the past. He has survived them and learned from the consequences.

“If, physically, I can get back to a good level my tennis is still fine,” he says. “I’m sure that, tennis-wise, I will be able to keep up with guys. I don’t feel that the game has moved on and I won’t be able to get back. A lot of the same guys are still there.”

It has been starkly illustrated in the first week here that the expected rise of the young contenders in the men’s game is still in its early stages, as, one by one, they have fallen. The sixth seed, Alexander Zverev, went out in the first round along with the seventh, Stefanos Tsitsipas, followed by the Canadian teenager Félix Auger-Aliassime in the third round.

A slew of prospects and established seeds have failed to reach the second week. From one side of the draw alone Kevin Anderson, last year’s finalist and the fourth seed, has gone, along with the three-slam champion Stan Wawrinka, 10th seed Karen Khachanov, 11th seed Daniil Medvedev, as well as Britain’s Kyle Edmund. Gone also, after a fighting exit on Saturday night, is back-in-form Dan Evans.

On the other side of the draw notable casualties include Dominic Thiem, Nick Kyrgios, John Isner, Marin Cilic, Denis Shapovalov and Alex de Minaur. Still standing, of course, are Djokovic, Nadal and Federer, along with Kei Nishikori, the only top-10 players left.

Murray, meanwhile, is determined to play his one remaining card for as long as he can, having lost in the first round of the men’s doubles earlier on Saturday. But did he not miss the cut and thrust of high-grade singles, though? Yes and no.

Andy Murray celebrates winning the doubles title at Queen’s. Photograph: Tim Ireland/AP

“It’s just different, singles and doubles. There is a lot more self-analysis in singles. It’s your responsibility. The thing that is nice with doubles is that, when you win, you are winning with someone else and that is enjoyable.

“When me and Feli [López] won at Queen’s, we went out and bonded with each other, had dinner and that sort of stuff. In singles at the end of matches it is on you and that is the thing I’ve always had that is kind of different to doubles really.

“At Queen’s, for example, we won the end of that final because of Feli. He played brilliant at the end of the match. So it is difficult to know how responsible you were for certain things. That’s the thing that is different about it that I am not used to as much.”

For all that he is enjoying his mixed doubles experiment with Williams, there is a murmur beneath that strongly suggests he cannot wait to get back to being a champion again – on his own.