Nicolás Almagro, a 31-year-old, former top-10 tennis player from Spain, sobbed on the court after he was forced to retire from his second-round French Open match today against Juan Martin del Potro due to a knee injury—the same injury that caused him to withdraw from a match against Rafael Nadal last month in Rome.

Almagro, no doubt frustrated and in pain, made no move to return del Potro’s serve and then keeled over on the court. His loud crying echoed around the stadium. Del Potro, who’s endured his share of debilitating injuries over his career, hopped the net to console his opponent.

Almagro, who’s won 13 singles titles in his career—all on clay—retired with the score tied at one set a piece, 1-1 in the third set.