Back in late May, a league source familiar with the Celtics’ line of thinking brought up Marcus Smart, the bullish guard out of Oklahoma State and a top prospect for this year’s NBA Draft.

“He must have something that they like because he’s pretty high in their draft rankings,” the source said. “For whatever reason, they really, really like him.”

The Celtics twice brought Smart in for predraft workouts, and then president of basketball operations Danny Ainge attended a third workout elsewhere.

Truly, the team had its eye on him for some time, it snatched him up with the No. 6 overall pick Thursday.

“He’s come in here twice in the last three weeks,” said Celtics coach Brad Stevens, “and we’ve absolutely fallen in love with his leadership and his work ethic and his spirit and how he goes about things.”

It might not have been a “fireworks” move that fans were hoping for after Celtics co-owner Wyc Grousbeck used that term to describe the possibility of big offseason moves, especially with players such as Arizona’s Aaron Gordon and Kansas 7-footer Joel Embiid off the board.