BOSTON – Five months after suffering a season-ending meniscus injury, Daniel Theis is nearly back to playing full-scale basketball.

And the process of getting to this point has taught him an unexpected new skill.

Theis, who tore his left meniscus during a March 11 matchup with the Indiana Pacers at TD Garden, has been inching his way back into basketball activities during recent weeks. He says that he has made rapid improvements during the early parts of August.

“Since I’ve been back (from Germany) – it’s almost two weeks now – I’ve been getting step-by-step progress and doing more,” he told Celtics.com during an exclusive interview at Boston’s new practice facility. “I’ve been doing jump shots, sprints, cutting, change of direction, jumping, so more basketball-like. Over the summer it was more preparing the knee, doing a lot of exercise, lifting.”

Theis said his most recent progress has finally brought the light at the end of his rehabilitation tunnel into vision.

“I’m just happy because now I see the goal to being back on the court and playing 5-on-5,” he said. “Now it’s just day-by-day, and I progress every day and get new stuff to do. From Monday, I was just running ‘S-curves.’ Today, I was hard-cutting and sprinting.”

The big man, who averaged 12.7 points, 10.5 rebounds and 1.8 blocks per 36 minutes during his rookie season, said that he’s “going to be 100 percent” for the start of training camp, which arrives Sept. 25, but there is no set date for his return to live action.

There were high levels of enthusiasm and excitement in Theis’ voice as he spoke about approaching the finish line of his rehabilitation. To the contrary, those levels were at ground level just a few months ago as he struggled through the low points of the first in-season injury of his basketball career.

Theis was injured just as Boston was beginning to make its final push toward the Playoffs, and an eventual push toward a berth into the NBA Finals. He was planning to be a key part of all of that, and then, in an instant, he wasn’t. That dart from one end of the spectrum to the other took a significant toll on his psyche.

“I never missed a single game of the season,” he said, speaking of his career. “So this time, we as a team and I worked so hard to get to the Playoffs, and then in mid-March when I got hurt, it hurt not just my knee, it hurt me. I can’t be on the court anymore and fight with the team.”

As he coped with that realization, he also came face-to-face with another harsh reality: that this rehabilitation would be dreadfully monotonous and lengthy.

“At the beginning, when I got hurt, I tried to come back as quick as I can, and the docs and trainers just told me that I need to be patient and I need to take my time and it needs time to heal,” he recalled. “You can’t rush this process.”

Due to the timing of the injury, that process would go on to engulf his entire offseason.

“Normally it’s like you take one, two, maybe three weeks off and get away from basketball and get away from sports a little bit,” Theis said of a standard offseason. “This summer was just working out basically every day. I had one or two days off, but I knew I needed to work out just to be back, and so my knee was prepared and ready when I came back here (to Boston) to process the new stuff.”

As he nears the completion of his rehab, and with all but five weeks of the offseason in the rearview mirror, Theis now looks back on the process and realizes that it taught him a valuable life-lesson.

“I’ve never been a patient guy,” he said with a laugh. “If I hear something, I want to do it right away. It’s been five months, and that changed. I learned how to be patient and go step-by-step, day-by-day.

“Over the course of the injury and over the summer, I also got more patient at home, and more calm, and I just learned how to do this.”

At this point, there isn’t much of ‘this’ left for Theis to endure. He’s inching closer to full basketball activity, and soon enough, he’ll return to live action.

When he does, he’ll be able to take solace in the fact that he’s added a newfound skill during his lengthy recovery process. He has added patience to his repertoire – though he hopes to never need to call on it again when it comes to injuries.