After losing to Murray in the first round of the Barclays Dubai Tennis Championships back in March, Federer criticised his opponent's style of play. "It sort of works for him, but he's going to have to grind very hard for the next few years if he keeps playing this way," said the Swiss at the time. "He stands way far behind on the court and (that means] you've got to do a lot of running, and he tends to wait a lot for the mistake of the opponent."

Clearly unimpressed by what Murray had to offer on court, Federer added: "I gave him the mistakes today, but I think overall, over a 15-year career, you want to look to win a point more often than for the guy to miss. That's what served me well over the years but, who knows, he might surprise us all and do it for 20 years."

Fast forward six months and Federer has changed his tune. Now, following his US Open final victory over Murray in New York on Monday night, the 13-times grand slam winner says the 21-year-old from Dunblane will one day hit the heights.

When the former world No1 was asked what it would take for Murray to take the next step and win a grand slam tournament himself, Federer said: "I don't think a whole lot. I think he's got himself in better physical shape. So, from that standpoint, he's better than ever."

Federer, now just one grand slam title behind record-holder Pete Sampras, added that experiencing a first major final had plenty of pitfalls but tipped the Scot to be all the better for it. "I think with finals like this, he knows now what it takes to get very far into a grand slam," he explained.

"It takes a toll on you emotionally, as well, because all of a sudden there's all the attention you ever wanted, but what you really want to do is focus on getting the title. I think by putting yourself in those types of positions, giving yourself opportunities, he'll only get bigger.

"I always thought he was a big-match player. Give him the biggest court in the world, he will have no problem handling it. I think that's what he's shown anyway throughout his career."

Until his 6-2, 7-5, 6-2 win over Murray in the Arthur Ashe Stadium, Federer had been having, by his standards, a lean season. Fans and pundits alike had been predicting the player's swift demise from the top of the game, but the Swiss master sees his year differently.

"It's better than 2003 when I made the breakthrough and won Wimbledon," he said in New York. "I lost in the first round in Paris (in 2003] so obviously it's way better. If it's a good, a great or a super year, it doesn't matter for me. I got the grand slam I wanted.

"I always say one grand slam (a year] in my eyes saves a season. That's definitively what it did. But 'saving a season' doesn't sound right. I proved to myself that I was doing the right things. I played excellent towards the end of the tournament and it's the first time I felt invincible again for a change."