In the 12 months since Andy Murray last played Roger Federer, rather a lot has changed for both men.
While Murray became the Wimbledon champion in July, a series of injuries caused Federer to fall a peg or two from the highs he enjoyed for much of the previous decade. Yet when the pair meet in the quarter-finals of the Australian Open tomorrow, both have something to prove.
For Murray, who defeated Federer in five sets in the semi-finals here last year, it is about showing that he is fully over the back issues which required surgery in September and is ready to add to his two grand slam victories. Yesterday, the Scot dropped his first set of the tournament but overcame Stephane Robert of France 6-1, 6-2, 6-7, 6-2 - a minor lapse in concentration costing him a straight-sets victory when he let slip four match points to the world No.119 in the third set.
For Federer, who sprang into life last night with a straight-sets win over Jo-Wilfried Tsonga, it is about proving that, even at the age of 32, he truly belongs in the equation when it comes to the trophies being handed out.
When Murray was beaten by Federer in the Wimbledon final in 2012, the Scot was left with lingering doubts that he could really win a big crown. That was all wiped away by a gold medal at the Olympics a month later, followed by his first grand slam title in New York later that year and then his outstanding run to the title at Wimbledon last summer.
In terms of pressure, there is no contest between a Wimbledon final and an Australian Open quarter-final, but Murray has been doing his best to tell everyone that even being at this stage is an achievement. But do not be fooled by Murray's words; his actions would suggest that his game is in pretty good shape and, if he is feeling 100% fit, he will fancy his chances against Federer, a man the Scot has beaten 11 times in their 20 matches. That includes victories in three of their past four meetings.
"It just depends on the day," the 26-year-old said. "I need to play a great match. If I strike the ball like I did for the first two and a half sets [against Robert], I'll give myself an opportunity in the match.
"I can't say my expectations are as high as if I'd been playing for the last four months. It's been a good effort so far to get to the quarter-finals of a slam this soon after back surgery. So I'm happy with that, but I'm not far away from winning the event. Anyone that's in the quarters is close. I just look forward to that match and hopefully playing a good one."
Despite the heartache he has suffered at his hands - Murray has lost to Federer in three grand slam finals - the Scot enjoys their matches, believing that his baseline game is a match for Federer's attack.
"It's always going to be special playing against him," he said. "I've played him 20 times so you know how you need to play against him, tactically things that work and things that don't work.
"Last year is pretty relevant because it's on the same court and it will be under the same conditions. But if you play 10% below your best, you can be off the court quickly. So whether my tactics are great or not, I need to play a great match to win."
With a new, larger-headed racket and Stefan Edberg having joined his coaching team, there has been a spring in Federer's stride over this past fortnight.
"Fedberg", as their collaboration has been nicknamed, has given the Swiss a lift and even if it is probably too early to give Edberg too much credit, Federer showed much more attacking intent last night as he beat Tsonga 6-3, 7-5, 6-4. It was as good a Federer as we have seen in months and the 17-time grand slam champion was more than encouraged.
"I'm extremely happy how things went for me tonight," said the Swiss. "I was able to play my game, offensive, mix it up, come to the net. Yeah, I was surprised that things worked out for me."
Federer came forward more than usual but it was his ability to nullify the Tsonga power that enabled him to dominate. "I was hoping I could play a little bit aggressive and I think it worked out better than I thought it would," he said. "I was good at the net. I was consistent. I was solid. I was quick. I had the right mindset."
Since falling from the world No.1 spot he had regained after winning Wimbledon in 2012, Federer has talked of doubts, fears and of weaknesses - things that in his pomp, he had no need to even mention.
This time he sees himself and Murray in the same boat. "I think we're both coming into this match with a good feeling but we're both coming into this match with some slight doubts, too," said Federer. "It will be interesting, because we had an interesting year last year with some ups and downs. It's a good start to the season for both of us already."
One of the problems for Murray and Federer is that if they are going to win the title, they will almost certainly have to beat the world No.1, Rafael Nadal, in the semi-finals and then Novak Djokovic in the final.
It is an incredibly tough task, so both men will be hoping that Grigor Dimitrov - the Bulgarian who is appearing in his first grand slam quarter-final - can test the Spaniard and drain a little of his seemingly boundless energy.
Finally, Dimitrov, the boyfriend of Maria Sharapova, is beginning to fulfil his potential. Whether he is quite good enough yet to beat Nadal, though, is another question altogether.