Tennis legend Roger Federer wrote a heartfelt letter to Rafael Nadal on Tuesday before the Spanish star joins him in retirement. Nadal is participating in the Davis Cup in Malaga, Spain this week before saying goodbye to the sport he has played professionally since 2001.

Although the relationship between Rafael Nadal and Roger Federer appears to be peachy on the outside, the pair are far from being pen pals despite ditching their differences

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