World number one Rafael Nadal has certainly not enjoyed the best of starts to the 2018 season, but the injury-plagued Spaniard has received some cheer from a most unlikely source - a 92-year-old superfan.Nadal was forced to retire from a grand slam match for only the second time in his career at last month's Australian Open when he withdrew during the final set of his quarter-final clash with Croatia's Marin Cilic due to a hip injury. Nadal has also suffered early exits at each of the other tournaments he has participated in this year.He will have been buoyed, however, by a letter of support from a great-grandmother which has gone viral on Twitter. The letter was originally posted online by the elderly fan's great-granddaughter, Debora Mansur, but has since been retweeted and liked thousands of times."Dear Rafa, in December I wrote you another letter and sent it to the Baleares academy, but they may not have received it. I am a woman of 92, almost 93, in April, and I am a great fan of your since you started playing tennis, " the lady began, before confirming that she was such an avid fan of Nadal that she would watch him live regardless of the time.“I watch all your games and if it's at midnight, I set the alarm," she said.The widowed fan then lamented both the Spaniard's injury woes and the fact that she would be unable to travel to Acapulco, where Nadal is due to play in the Mexican Open, beginning on February 26."I feel a lot for what happened in Australia and I wish that everything goes well. Now you will be in Acapulco late this month, I would have loved to go there, but it's difficult for me to travel. My husband, that died, played tennis a lot I think that's why I liked it."She concluded her letter by simply saying "I would really love that you reply". The unnamed lady would soon have her wish.Nadal was clearly touched by the fan's words upon learning of her letter. In a gesture of both class and kindness, he responded to the author's great-granddaughter with a tweet of his own in which Nadal expressed his gratitude for the letter which had "reached the heart".

“Dear Debora, please, thank your great-grandmother from me for this emotional letter and her content that reaches the heart. All the letters and supports message that I have received from all of you mean a lot to me. Many thanks."

Nadal will have the opportunity to bounce back on the big stage during his next grand slam appearance, which will take place at the French Open this summer.

Nadal will be looking to secure his 11th tournament triumph and the Spaniard is sure to have fans, both young and old, glued to their televisions to see if he can add to his record-breaking resume at Roland Garros.