ROTTERDAM (Reuters) - As arguably the greatest ever tennis player, Roger Federer is urging Olympic officials to back another racket sport by including squash in the program for the 2020 Games.

"I really like the sport and I even used to play it in my younger days but that was with a wooden racket," 17-times grand slam champion Federer told Reuters after he suffered a surprise defeat in the quarter-finals of the World Indoor Tournament on Friday.

"There are some great characters active in the sport and I believe that they deserve to be present at the Olympics."

Martial arts karate and wushu, rollersports, wakeboarding, squash, sports climbing, wrestling and a joint bid by baseball and softball are the candidates for the one open spot for the 2020 Games.

(Reporting by Theo Ruizenaar, editing by Pritha Sarkar)