Letter writing is a dying art in the digital age, which will make life harder for the biographers of the future. But wouldn't it be great if Roger Federer and Rafael Nadal, great friends and rivals who stunned everyone by slashing their way to the Australian Open final, shared some of their innermost thoughts in writing before they meet in a Grand Slam final for the ninth time? Let's imagine how that correspondence might go:

Dear Rafa:

How goes it? It seems like just yesterday that we were together in your home town of Manacor in October, celebrating the opening of your academy. Two banged-up old dudes whose future prospects ranged from bleak to mildly encouraging, you because of that bad wrist and me with the knee thing. Now here we are, about to make some serious history again at a time when lots of people didn't think we could find our way to another Grand Slam final with the aid of GPS.

But yeah, it's on. Happy days are here again, even if I'm still not officially Sir Roger Federer and you don't have a personal guru schooling you in the ways of peace and love. LOL!

You know, I was being utterly sincere in my on-court, postmatch interview the other day with Jim Courier, when I said of you:

Roger Federer is looking for his fifth career Australian Open championship. His last one came in 2010. SAEED KHAN/AFP/Getty Images

"He's an incredible tennis player. He's got shots that no other one has. When you have that, you are unique and special. Plus, he's got the grit. He's got the mental and physical ability to sustain a super-high level of play for years and for hours and for weeks. He's proven that time and time again. He's come back from many injuries, you know, time and time again. He made it seem easy, and it's not. I think he's been tremendous for the game. I have a lot of respect for him on many levels."

The most relevant "level" right now is your longevity, which is something I quite frankly never expected -- not with the way you have always had to grind through matches, not with those huge cuts you take and the torque you have to apply to get that topspin. Your overall style is physically and mentally exhausting. Over the years, that's got to exact an enormous toll, but despite that history of arm and knee injuries, here you are again.

People are calling our arrival in the final an "amazing achievement." I have to admit that I don't see it as so "amazing" at all, but I guess this is why some people mistake my honesty for arrogance, just as so many mistake your humility for false modesty. Why shouldn't I say I played a great match when it's just what I did, hitting shots that bring tears to a knowledgeable fan's eyes?

To me, our performances this fortnight just validate our simultaneous decisions to skip the back end of 2016. As I told the press the other day, it seems we both decided, "Let's get back to 100 percent, enjoy tennis, enjoy the practice." Not just practice, treatment, practice, treatment, match, treatment ... over and over. We were in a bit of a rut.

Rafa, it's kind of sad, but we're not kids anymore. Hey, I even took a medical timeout during my semifinal against Stan Wawrinka the other day, and you know how I feel about those. LOL!

As we prepare for this match, I want you to know how much I have appreciated your place in my life. I needed you the way Martina needed Chrissie, or Magic needed Bird, or Athens needed Sparta. The contrast in our styles, between my magical, fluid game and your bullish power and retrieving, it took tennis to another level. What I do not particularly need, though, is a threat to my secure status as the Greatest of All Time in the men's game. And I must say that's a bit of a cloud that passes now and then over our wonderful friendship.

This is an awkward issue to bring up, and one I didn't expect to have to face, but here we are. I have heard the whispers, some of them from prominent people like Andy Roddick, suggesting that if you win this match and close the gap in Grand Slam singles titles to 17-15 in my favor, the GOAT conversation is automatically reopened.

Look into your heart, Rafa -- do you think that would be fair?

Sure, a win would boost your lead in head-to-head matches to 24-11. But let's be honest, it's a lopsided number partly because, while you are the undisputed "King of Clay," I repeatedly challenged you in clay-court semis and finals. You, on the other hand, didn't always show up to meet me on faster surfaces where I had the advantage.

Enough! I want you to know that however it goes tomorrow, your friendship means a lot to me, and I look forward to meeting you in many more Slam finals. Maybe we're just getting started!

All the best, big shout-out to your Uncle Toni and coach Carlos Moya (he's been doing great work, BTW),

Roger

To which Nadal might reply:

Dear Roger:

I was very surprised to receive your letter, but my reply must be short because it is late and we have big match to play Sunday, no? You have an extra day of rest after the semifinals, but that's OK -- I might be 30, but you are five years older! LOL!

I am feeling very sentimental about this final. It is our ninth meeting at this stage in a major, and no two men in the Open era have equaled that. It is true that I prefer you as my opponent in the final. That isn't because I've won six of our eight finals, but the contrast you speak about.

That contrast doesn't exist when I play against Novak Djokovic, who made my life so difficult starting in 2011. It has been so nice this last week not having him around. It has been very fun, like old times. Do you remember what I said about you when you defeated me in the semifinal of the Tennis Masters Cup in 2007?

"If he is playing very good, I have to play unbelievable. If not, it's impossible, especially if he's playing with good confidence. When he's 100 percent, he's playing in another league. It's impossible to stop him. I fight. I fight. I fight. Nothing to say. Just congratulate him."

Rafael Nadal is one win from his first Australian Open championship since 2009, his only victory at Melbourne's Grand Slam. Michael Dodge/Getty Images

This is still true. You are still in my opinion the greatest, you and Rod Laver. I don't know if that will change in the future or not. For sure, not on Sunday, whatever happens in Rod Laver Arena.

But also I want to be honest and say it was a little unfair when you said to the press this week that maybe I won Wimbledon in 2008 because I defeated you a few weeks before in French Open final. You explained:

"Maybe I lost the Wimbledon finals in 2008 because of too many clay court matches, because he [Nadal] crushed me at the French Open final. I said that before. I think it affected my first two sets at Wimbledon. Maybe that's why I ended up losing. I know Rafa played great in that [Wimbledon] final. I actually ended up playing great, too. ... [But] I wasn't fighting the right way. I think that was the effect that the French Open loss that I actually got crushed in left on me."

Roger, that was one of the best periods of my career, maybe the high point, when I finally won Wimbledon after losing two finals to you. I think it's unfair that you said that. You are not an arrogant person. I don't think I am, either. It is true you had a bad day when you won just four games in the French Open final in 2008, but I don't think that had anything to do with the Wimbledon match.

So I just wanted to say that.

I agree with you in this conversation about the GOAT. Let other people discuss about it and decide. Our careers are not over yet anyway. Who knows how many Grand Slam finals we may still play? Now is just the time for us to enjoy because we have proved something. We have achieved a lot. We are healthy and, for now, the two best men's players in the world again. It's time for us and the rest of the world to enjoy it.

Big hello to Mirka. The kids are getting so big! See you Sunday,

Rafa