"I have been going back and forth the last few weeks trying to figure out the right things to say, and it comes down to two simple words: THANK YOU!"
Popovich and Leonard appeared to have a fractured relationship at times during the Leonard's final year in San Antonio, when the disgruntled forward suited up for just nine games due to injury.
Leonard was effusive in his praise of the Spurs' fans, who watched him blossom into one of the game's premier two-way players over the first seven seasons of his career.
Leonard - who now plays for the Toronto Raptors - thanked his the Spurs organization and the San Antonio community for the successful years they had together.
He also thanked the city of San Antonio, his former teammates and the fans.
Though some are more heartfelt and less robotic, thank-you letters by traded players rarely say much significantly.
"Through ups and downs - glad there were many more ups!"
While last season was one to forget for Leonard, his time in San Antonio will be better defined by his 2013-14 campaign, when he helped the Spurs capture their fifth National Basketball Association title while being named MVP of the Finals.
Kawhi Leonard hasn't spoken publicly in months, as he last met with the media prior to his self-imposed exile from the Spurs to NY to rehab his quad injury.
There was speculation that Leonard would not play for Toronto, as his preference was to head to Los Angeles and play for the Lakers.