T.J. McConnell’s NBA career started on a sour note thanks to the Boston Celtics.

McConnell, who’s coming off his fourth season with the Philadelphia 76ers, debuted against Boston in 2015, and Celtics head coach Brad Stevens evidently wasted no time in making the point guard’s life a living hell.

Here’s McConnell’s funny story, which he recently told on “The Woj Pod” podcast, hosted by ESPN’s Adrian Wojnarowski:

“It was one of the most embarrassing moments of my life, and one of those gut-check moments where Isaiah Thomas, in my opinion one of the most unguardable guys that I’ve played against, and you got a coach like Brad Stevens — they called a play as soon as I checked in and Isaiah came off, scored. I come back down, Boston brings the ball back down, I look over at Brad and he goes, ‘Again.’

“And Isaiah gets someone a lob. We go back down, don’t score and I look over at Brad and he goes, ‘Again.’ I’m like ‘Oh, my goodness gracious.’ And Isaiah scores again.

“I think I got subbed out after that and I was like, ‘Welcome to the NBA.’ “

There’s no shame in being exploited by Stevens, one of the NBA’s best coaches, or schooled by Thomas, who earned his first of back-to-back All-Star selections with Boston in 2015-16. That’s especially true for an undrafted rookie appearing in his first NBA regular season game.

It’s clear McConnell, now 27, never will forget the humbling experience at TD Garden, which probably was the least of the Sixers’ concerns at that point, for Philly started the 2015-16 campaign with a 1-30 record en route to a 10-72 finish.

Thumbnail photo via Greg M. Cooper/USA TODAY Sports Images