After injury woes, the reinvention of Arthur Fils is a work in progress

Where many would've seen misfortune, Arthur Fils saw opportunity.

Sidelined from the tennis tour for nearly eight months from last spring until last month with a debilitating back injury, the 21-year-old Frenchman refined and refreshed his game.

Through to the quarterfinals at the BNP Paribas Open for the second straight year, Fils detailed just how, technically, he changed his tennis in his time away, which included shortening his forehand take-back. That reveal followed an early-season confession that he retooled his diet with the help of a nutritionist.

Read more: Arthur Fils gives health update with launch of new YouTube channel

"We've worked on a couple of things, the serve, the forehand, even the movement on the court with the fitness coach," he said after beating Felix Auger-Aliassime in the fourth round. "We work on a lot of things, and even now we are still working on it. We're trying to improve every day, and it's working pretty good.

"I was moving good, but sometimes I was wasting a lot of energy ... we had a great talk with my fitness coach, my tennis coach and the whole team that said I can move even better without wasting that much energy. So that's what we are trying to do now. Of course, when it gets very tight, I start to move crazy again! You have to chase the ball, right? But I think we're doing great work."

Matching his result from 12 months ago seemed improbable when you consider how little Fils played in the months since. But his eighth career Top 10 victory put him into an exclusive club.

According to the ATP, he is the third Frenchman to achieve the feat in tournament history after 1982 champion Yannick Noah (1982-84, 1986-87) and Thierry Tulasne (1986-87).

Fils will next meet Alexander Zverev, who he has already faced six times. Their rivalry has, at times, been spicy, but as far as Fils is concerned, if his body is right, and his mind is focused, then the results will speak for themselves as his comeback continues.

Read more: Alexander Zverev vs. Arthur Fils: Where to Watch, Preview and Prediction

"The points, they leave, they come back, it's OK," he said of his current perch of No. 32 in the ATP rankings. "Sometimes you win some matches; sometimes you lose some. The points is not a big pressure for me.

"The only pressure that I got was would I be able to come back to my level to where I left, you know. That was the only question. You know, I talk a lot with my team, my friends about it. I'm, like, 'Well, I know I will be back, but what level?'

"I just had to keep working, stay very patient, like you said, because it's long, it's a long process. ... So [I] just stay very focused on the work, try to not watch the other players because, well, it's nice to watch them for one tournament or a second tournament, but then you start to feel, OK, the guys are improving a lot.

"Me ... I don't know how I'm gonna be after [the injury], so just try to focus on myself, my way to be back. And, yeah, I think we made a great job."