The Oklahoma City Thunder and San Antonio Spurs are carving out one of the best NBA rivalries in recent history. Sure, they're not the legendary status of the Los Angeles Lakers and Boston Celtics, but the last two decades have shown some extremely rich and successful hoops.

After the Thunder were bested in an epic seven-game duel in the 2026 Western Conference Finals, the Spurs added a new character to the ongoing rivalry that will surely include another chapter in the 2027 NBA playoffs. After falling short in the 2026 NBA Finals, Mitch Johnson added a veteran voice in Billy Donovan.

Donovan is taking on a new NBA venture. This time, he'll be a Spurs assistant. It's the first time he's had that job description since *checks notes*... 1994? Yeesh. Most of the current crop of NBA players weren't even born when he had that gig at Kentucky.

After a legendary run at Florida, Donovan has been in the NBA for over a decade. First, a four-year stop in OKC. And then six long years on the Chicago Bulls. Now, the 61-year-old is taking a step back. He's going to lend his expertise and experience to Johnson — who's only entering his third year as the Spurs' head coach.

On opposite sides of the sidelines for Opening Night, Thunder head coach Mark Daigneault is stoked for Donovan's new role. He believes he's going to help the Spurs handle title expectations. After last year's run, San Antonio won't sneak up on teams any longer.

"He'll embrace it. There's a reason he's doing it. He loves to coach. He loves basketball. He loves competing. Loves being around it," Daigneault said. "I don't know how many people, if I'm being honest, are humble enough to go in the Hall of Fame in September and then take an assistant coaching job in May or June. But he's one of them."

Of course, Donovan and Daigneault have a Jedi-Padawan dynamic. After all, Donovan added Daigneault as a Florida assistant from 2010-14. And fun fact — Daigneault actually preceded Donovan in their respective starts at OKC. The former was the G League's OKC Blue head coach from 2014-19. Donovan became the Thunder head coach from 2015-20.

In their time together, they were on the same NBA staff just once in the 2019-20 season. Daigneault briefly became an OKC assistant before he took over the reins. Anytime you ask Daigneault about Donovan's mentorship, he always has positive reviews about their time together.

Now, Daigneault's past with Donovan adds another new interesting wrinkle to the Thunder-Spurs beef. It's a fun subplot that grows another tentacle between the two NBA franchises.

"He's a unique, original guy, and that's just the latest example of it. He'll add tremendous value to them. I give Mitch a lot of credit. It takes a lot of humility to add somebody with that pedigree," Daigneault said. "They'll both benefit from that because they both have the humility to do so. He'll be a huge asset to them."