Springer struggled to see the floor after joining the Celtics, though. He was behind one of the best guard rotations in the NBA, one that would help lead Boston to a title. On Saturday, though, the young guard got his chance to impress during Boston’s 119-114 loss to the Miami Heat in the Las Vegas Summer League.

The young guard put on an excellent display and blended his offensive and defensive responsibilities well, finishing the game with 23 points, six assists and two steals while shooting 53.3% from the field and 50% from three-point range (on six attempts). However, it’s his defensive versatility that should entice Joe Mazzulla to find a spot for him in Boston’s rotation next season.

Springer’s ability to guard multiple positions, produce elite point-of-attack defensive pressure and hold his own when being switched onto opposing bigs fits directly into how Mazzulla’s defensive philosophy.

Boston’s guard rotation is likely set. The duo of Jrue Holiday and Derrick White were formidable last season and proved themselves to be the best two-way backcourt in the NBA.

Payton Pritchard also grew in stature throughout the season and is a reliable ball-handler off the bench. Nevertheless, Springer’s upside can’t be ignored.

Springer, 21, is entering the final year of his contract and will be a restricted free agent next summer. Boston has a raw talent that could develop into a defensive pitbull off the bench. The franchise has been good at developing younger talent in recent years.

Springer was acquired in part because of Cassell’s recommendation. Now, the Celtics must give him a chance to develop and prove himself within the rotation.

If the young guard continues to thrive in Summer League, it will be hard to ignore him once the season begins this fall.