During his post-practice shooting session, the 6-foot-6 rookie took one 3-point shot after another with some going in but too many for Langford's liking, not.
Finding that perfect stroke, that perfect catch-release-swish rhythm, was the mission Langford was hell-bent on completing.
And as he finally made his way towards the locker room, the rookie reminded us that this was the first time we had seen him practice and the extra time that may have seemed out of the ordinary to us, was just another day at the office for him.
"I put extra work in every single time, after practice," Langford told NBC Sports Boston. "Today I needed a little bit more time to get my shots up."
Langford's practice routine is one of the many unknowns surrounding the Celtics rookie who was taken with the 14th overall selection in June's NBA draft.
There's an element of uncertainty surrounding all rookies when they come into the NBA, regardless of where they are drafted.
But with Langford, the usual lack of clarity you expect because he's a rookie, is only magnified by his lack of court time since the draft.
Surgery to repair a torn ligament on his right (shooting hand) thumb, kept Langford sidelined for all of summer league while Boston's other rookies shined during summer league play.
More significant, the injury was one Langford suffered early in his lone season with the Hoosiers but didn't result in him missing any significant amount of time.
Rather than have surgery which would have kept him sidelined for several weeks or potentially all season depending on when he would have had it done, Langford opted to play the final 26 games of the season with the torn ligament.
"He's a quiet kid and because of that, people sometimes get ideas about him not being tough or working hard or not being a leader and all that stuff," an Eastern Conference scout told NBC Sports Boston. "But this kid can play. Think about this. He went to Indiana with everyone knowing he was one-and-done. He took a huge gamble playing with that injury because it could have hurt his draft status more than it already did. Let's put it this way. He had a lot - a lot - more to lose by playing than gain. He didn't care. He wanted to be there for those guys because he knew he was gone after one year. The Celtics got a kid who is a lot tougher than people realize."
Since getting the green light to resume full contact, Langford's teammates said he has made up for the lost time with some impressive play during pick-up games at the practice facility prior to the start of training camp.
Fellow rookie Carsen Edwards has been competing with Langford for years on the prep basketball scene in addition to last season when Edwards was at Purdue and Langford played for Indiana.
"He's a scorer, man," Edwards told NBC Sports Boston's Kyle Draper regarding Langford. "He can score at all three levels, whether that's mid-range, the 3 or get to the rim. He's real athletic, long arms, can finish around big guys and take off from outside the paint and finish. He has a good feel for the game."
And a good work ethic, evident by his longer-than-necessary hours spent following his first practice.
More than anything, he wants to be as ready as possible when his number is called.
"I'm a team player. I do whatever is called for me to do when I get out on the floor," Langford said. "Whatever minutes I get, I'm going to give it all I got."
In the past, Langford's dynamic play has been in stark contrast to his low-key demeanor.
How much of a contrast we see this year, remains to be seen.
"I'm not the most … outgoing person," Langford said before breaking into a slight smile, "but I'm definitely not quiet once you get to know me."
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There's a lot to love about Celtics mystery man, Romeo Langford originally appeared on NBC Sports Boston