Nadal reveals text to Federer after Australian Open

Roger Federer left Melbourne with Grand Slam No. 20 and the congratulations poured in from around the globe. One person who didn't forget to share his support was the Swiss' greatest rival Rafael Nadal.

"I immediately sent him a text message," Nadal said at the opening of the Mapfre Clinic of Tennis Medicine in Madrid. "I usually congratulate people I know in private rather than publicly. I've had a very good relationship with Federer for years now. I was happy for him; I congratulated him and I told him I'm always happy when he does well."

In Melbourne, Nadal retired in the fifth set against Marin Cilic in the quarterfinals with a leg injury. Federer would beat Marin Cilic in the final.

The world No. 1-ranked Nadal is currently just 155 points ahead of Federer in the rankings. He's scheduled to play in Acapulco at the end of the month, while Federer just announced he will play Rotterdam next week.

"The tournament is special for me," Federer said about the ATP 500. "I remember playing for the first time in 1999 as it was one of the first events where I got the chance to play at the highest level. It feels good to join in the celebrations of the 45th edition."

If the 36-year-old reaches the semifinals in Rotterdam, he will become the oldest No. 1 ever.