This past summer, Renna Mohsen-Breen played tennis, on average, six days a week for about six hours each day.

She played so much that she developed tendinitis in her left wrist.

She shrugged it off and kept playing. Tendinitis turned into a stress fracture.

Her left hand, it was deemed, had to be shut down for six weeks. But, so what. Her doctor and her trainers told her that, sure, it was possible to play with one hand.

It was her call.

And for Mohsen-Breen, it was an easy one.

"I didn't stop playing at all," said Mohsen-Breen, the sophomore star for the Moorestown Friends girls' tennis team. "I just kept playing one-handed — just slicing and one-handed backhands."

That's what it takes, she said, to earn a Division I scholarship in women's tennis.

"And that's what I want," Mohsen-Breen said. "I want to play Division I tennis. I want to be a great tennis player. And I know that's what it takes to get there."

In just two years, Mohsen-Breen has developed a reputation for grit and mental and physical toughness. Her size — 5-foot-10 — and skills are elite. But it takes more than that to be an elite tennis player.

"She's the type of player," said her coach, Mike Bodary, "who never gives up. She's just so dedicated. From the time I saw her first play, she's just been tireless in her desire to improve herself and work hard."

There is arguably no harder road to the top collegiate echelon of any sport than tennis. In many other sports, just about every solid player has at least a decent chance to get a Division I look.

In girls' tennis, only about the top 75 nationally in each age group can hope for a Division I offer.

Fortunately, for Mohsen-Breen, that's right about where she is  floating. She's ranked No. 3 in the state.

She has been dominating her high school schedule. She's 20-1 — even while playing about half the season with one hand — and her only loss came on Sept. 9, a one-handed loss, to Vineland's Tess Fisher, a senior also among the top-ranked in the country.

But the high school season is not where Mohsen-Breen earned her spot in the national conversation — although it did give her a chance to develop parts of her game while she was bogged down with injury.

"In the past year, I've played in about 10 national tournaments, traveling all over the country," she said.

It's the reason  you didn't see her in this year's state singles tournament, a tournament in which, as a freshman, she advanced to the fourth round before falling to Andrea Cerdan of Paramus Catholic, who ended up winning the whole thing.

She opted to miss this year's tournament to play in a national tournament in Florida, where she was one of the top finishers in a field of 64 girls.

She shrugged off the results.

"Of course, I would have liked to have done better," she said. "But these experiences are great. And I just need to keep building off them."

That's pretty much required in tennis.

Mohsen-Breen started playing when she was 8 years old. Her talent was evident from the beginning. As she physically grew into her natural skill set, she realized that she could be great at the sport. And that's when her dedication really began.

Now, on most days after practice at Moorestown Friends, her parents will shuttle her to High Performance Tennis Academy in Bala Cynwyd, where she'll go through a few more hours of training. And, of course, she plays 12 months out of the year.

"It's really tough and my coaches there are super hard on me, but I think it gives me confidence," she said. "I think that's given me a lot of what I need when I go into a match and know that I've done all that training and know I have what it takes to get through it."

Still, it's easy to see how it could feel like a job.

But that's where high school tennis comes in.

In an era of specialization — where in sports like basketball and soccer, playing for your school isn't always a given anymore —  Mohsen-Breen is focused on an important, often overlooked, aspect of sports these days: having fun.

Through all of her tireless work, she still enjoys the sport. She loves the work she puts in. And that might be her biggest accomplishment.

"There's nothing like the team aspect of a sport, and that's what I have at Moorestown Friends. You laugh, you smile. You support your teammates.  You can be loud. And you can just have fun with it," she said. "It's a lot harder to play in the national tournaments because everybody wants to beat you. And here I think it's really nice because I love being with the team, it's so much fun and I think we're all really close. We're all working toward the same goals. And that's important."