Former Boston Celtics head coach Brad Stevens wasn't in the team huddle prior to Jayson Tatum's clutch shot to beat the Philadelphia 76ers on Saturday night, but that doesn't mean he wasn't a key part of the game-winning play.

According to current Celtics head coach Joe Mazzulla, Stevens originally drew up the scheme that helped seal Saturday's comeback win over the Philadelphia 76ers.

“I stole it from Brad,” Mazzulla said about the inspiration for the play, per The Athletic's Jared Weiss.

Although Stevens is now in the front office as the president of basketball operations after coaching Boston for eight seasons, he has been a big help to Mazzulla, who never had any head coaching experience at the NBA level prior to this year. How much help Mazzulla has received is unknown, yet at the very least, Stevens has lent his playbook to the 34-year-old coach.

While the game-winning play Saturday wasn't overly complicated — as it looked like a simple design for Tatum — it was highly effective. Tatum had enough space to make something happen after point guard Marcus Smart delivered him a precise bounce pass:

It seemed like even Tatum knew Mazzulla was drawing up something great. When ESPN tried to look in on the Boston huddle, he threw a towel over their cameras to totally block them out:

Philly likely knew a Tatum attempt was coming, but they still couldn't stop the dagger 3-pointer. The 24-year-old star has hit his fair share of big shots, and even though he didn't have it going for most of the outing, he delivered when it mattered:

The Sixers-Celtics rivalry never fails to entertain, and it will return on April 4 for the final regular-season meeting between the two Eastern Conference foes. It'll be another road game for the C's, who already had some contentious interactions with the Philly fans.

Whatever happens next, the NBA's longest rivalry doesn't seem to be slowing down anytime soon.