Roger Federer says Rafael Nadal made him enjoy tennis “even more” during a rivalry that spanned 40 matches over 15 years.

Writing on social media on Tuesday, hours before the start of the Davis Cup Final 8, Nadal’s last event before heading into retirement, Federer began his message with the word “Vamos” and said: “As you get ready to graduate from tennis, I’ve got a few things to share before I maybe get emotional.”