In 2010 Djokovic signed with Sergio Tacchini, and endured the most difficult patch of his career. He threw up on court in a five set loss to Jo-Wilfried Tsonga, and double faulted at 1-3 down in the fifth set, a moment he described as the lowest in his entire career. He then went on to lose from two sets to love up in the French Open quarter-final later that year against Jurgen Melzer.
At that time, Djokovic was diagnosed with a gluten allergy by a doctor who was coincidentally watching Djokovic's match with Tsonga on TV. He claimed he knew instantly why Djokovic was suffering physically, and infamously made Djokovic undergo several tests, including putting a slice of bread on his abdomen
In 2011, Djokovic finally put the pieces of the puzzle together, winning three slams, five masters, and going 11-1 against his great rivals Roger Federer and Rafael Nadal. That season was considered by many to be the greatest season in the history of tennis, both statistically, and in terms of the level of tennis Djokovic produced
