The letter reads: "Dear Dylan, I wanted to pass on my congratulations for your recent win at Wimbledon and your most popular new talent award!
"Thank you for the special contribution that you made to sharing the stories of wounded, injured and sick servicemen and women on the Invictus Games Today show.
"Your achievements are extraordinary, and the impact you have had in raising awareness and changing perceptions of disability is really inspiring.
"I wish you the very best of luck for the future, on-air and on-court!
"All the best, Harry
"PS - I'm wondering if you wore your Invictus Games budgie smugglers on the big night to accept it? Mine have come in handy in this recent UK heatwave!"
The moment refers to when Dylan jokingly presented Harry with a pair of budgie smugglers which the Duke of Sussex happily wore over his pants.
Of the moment, Dylan said: “We gave him a gift. One of the athletes, Matt, gave him a pair of budgie smugglers. And he put them on, over his jeans. It looks awesome."
Prince Harry and Meghan Markle will be attending the next Invictus Games at The Hague in 2020, with little baby Archie in tow.