He wasn't throwing it away.
To fix the issue of Leonard's nameplate on the back, Casa covered it with a silver strip of duct tape, and wrote "Aldridge" in black permanent marker. On both the front and back, he stuck a strip of black electrical tape vertically next to the 2 on the Leonard jersey to make it No. 12.
A San Antonio native, Casas explained how Leonard's departure back in July made him angry.
"Now, you're my favorite," Casas told LaMarcus Aldridge, as the Spurs big man laughed and signed the jersey.
I've seen two of these Kawhi-conversion jerseys tonight. pic.twitter.com/vsp7n94Unj— Michael C. Wright (@mikecwright) January 4, 2019
Two summers ago, Aldridge had requested a trade away from San Antonio. Now, here he was signing an autograph on the altered jersey of Leonard -- a player the Spurs didn't want to trade until they faced no other option -- as Leonard made his debut as a visitor to the AT&T Center.
That scene Thursday evening before San Antonio's 125-107 win over the Toronto Raptors served as the perfect summation of one of the strangest periods in Spurs lore, as the team finally closed the book on the Leonard chapter of its history.
Several fan bases and franchises can lay claim to having experienced a night like Thursday when a player, in this case Leonard, returns to face his former team after leaving on acrimonious terms.
But never in San Antonio, where David Robinson, Tim Duncan and Manu Ginobili all retired as career-long Spurs, and where Tony Parker is expected to receive a hero's welcome when he returns in two weeks with the Charlotte Hornets.
The fans let their voices be heard loudly on perhaps one of the most awkward nights in San Antonio Spurs history. They jeered Leonard at every turn, chanting "traitor" and "quitter" at him simultaneously, before directing MVP chants toward DeMar DeRozan, who notched his first career triple-double against his former team, having reluctantly arrived in San Antonio in the trade that shipped the two-time NBA Defensive Player of the Year to Toronto.
The truth is, the Spurs didn't enter this season with championship aspirations the way they do most years under coach Gregg Popovich. Initially, the goal was to just salvage what they could out of the trade they never wanted to make in the first place and somehow remain competitive through it all.
Now at 22-17, the Spurs find themselves in the thick of the battle for the West, just three games out of second place in the standings.
"It's always easy when you've got great guys around you that are willing to learn," DeRozan said. "This is a great group of guys that is willing to sacrifice whatever they need to for the next guy. When you have a team like that, karma definitely will be in your favor."
Kawhi catches up with Popovich after game
Kawhi Leonard talks with Gregg Popovich and ex-Spurs teammates after Toronto's 125-102 loss to San Antonio.
The Spurs entered this matchup against the Raptors wanting to keep any potential Leonard distractions to a minimum, which is the main reason they downplayed the notion that this outing meant something more than just a game. Popovich experienced firsthand in November how even mentioning Leonard, given recent history, could turn into a hot-button issue.
Asked about the leadership of Patty Mills in the wake of the retirement of Ginobili and Leonard's trade to Toronto, Popovich provided a blunt assessment of his former Finals MVP unintentionally, according to sources, as well as that of future Basketball Hall of Fame point guard Parker.
Popovich said at the time that, "Kawhi was a great player, but he wasn't a leader or anything." But Popovich was simply trying to say that the reserved Leonard, who came up on a team with veterans such as Duncan, Parker and Ginobili, hadn't yet developed into a vocal leader, preferring to focus on doing his job to the best of his ability.
"Knowing Pop and being with him for so many years, he never wanted to take a shot at Kawhi, not at all," Parker told ESPN. "That's not Pop's style. So I guess he was just saying that it was not Kawhi's thing, you know? Because the Big Three was there. Slowly but surely, [Leonard] was starting to do it. That was our goal with Timmy and Manu for him to do it more and more. Then when we were gone, he was gonna do it. And he was starting to do it. The people, they always want to exaggerate now."
With Leonard out of the picture now and the book of San Antonio's strange 2017-18 season finally closed, perhaps now everybody involved can finally move on.
Danny Green, who also was a part of the Leonard trade, made his return to San Antonio and received a warm reception from the fans at the AT&T Center throughout his warm-up and when he was introduced in the starting lineup. He hugged a Spurs PR staffer and a member of the security team, and on every clip that flashed Green's face during the tribute video that featured both he and Leonard, the crowd cheered.
Spurs display thank-you video for Kawhi, Green
Before the Raptors' starting lineup is announced, the Spurs show a thank-you video for Kawhi Leonard and Danny Green.
Leonard, meanwhile, was booed relentlessly throughout the night, even every time he touched the ball.
"I felt badly about it," Popovich said. "Kawhi's a high-character guy. We all make decisions in our lives, what we're going to do with our futures, and he has that same right as any of us. So, I felt badly in all honesty."
As Leonard received the boos from the floor, up in the stands, his uncle Dennis Robertson signed autographs for fans.
Even Leonard's best friend, Jeremy Castleberry, a former member of the San Antonio coaching staff who left to join Toronto's staff, walked down the hall inside the arena with an arm around a Spurs assistant coach.
So when Leonard acknowledged Thursday morning that "at times" he wishes things could have gone differently in San Antonio, you got the sense he's being sincere.
"This was really disappointing for all of us, from Pop and our program to our players," Spurs general manager R.C. Buford told ESPN. "We shared a lot of success together with Kawhi, and he was a very, very important part of that. So you end up doing a lot of self-evaluation and self-reflection when circumstances change.
"It would be irresponsible for me to speak for Kawhi, but I know he wants to be successful. I know he has always had a big impact and presence when in a team environment, and all I can say is while he was with us, it was an honor to sit back and share in his development both as a player and as a person."