PARIS—Comebacks are expected to be a theme at this year's French Open, particularly with Justine Henin returning as one of the favorites after ending an 18-month retirement earlier this year.

She looked almost like she had never been away, coasting to a 6-4, 6-3 victory over Tvsetana Pironkova on Tuesday.

"It's only my second Grand Slam, and even with all the experience I got in the past... I'm probably less consistent now than I was at the end of my career in terms of keeping the intensity all the time," said Henin, reflecting after the match on her return so far. "That's what I'm working on at the moment. That's not easy."

But Henin has certainly made it look easy, returning to the Top 20 in less than five months and reaching the Australian Open final in just her second event back. Fellow comeback queen Kim Clijsters did much the same last year, winning the U.S. Open in just her third event back.

Despite their high-profile success, however, they are the exception rather than the norm. The comeback trail tends to be a long and winding road instead of a straight trek back to the top.

The two Belgians were not only top players when they retired, they also had the benefit of being healthy and mentally rested when they decided to end their retirements. Extended breaks due to injury are a far bigger challenge, because players must strike a balance between returning as early as possible while not rushing their recovery.

A player who comes back not fully prepared will be eaten alive, as Dmitry Tursunov and Jelena Dokic found out on Monday, winning just a few games in their first-round exits.

"I actually only started hitting three weeks ago.... The week before here was actually my first real hard practice week. Obviously I need some time and some matches," said Dokic, who lost 6-2, 6-2 to Lucie Safarova.

"I'm already playing a tournament next week. Just need to keep on playing and practicing and keep on playing matches, I think," she said.

As tough as the drubbings are, getting match practice is a vital stage in the comeback process. "When you're coming back from surgeries and injuries, you can practice all you want to but you still want to see how far you are from where you need to be," said Tursunov, who was playing his first event since undergoing foot surgery last year.

The quirky Russian, best known for penning some hilarious blogs about the tour, says he is committed to his comeback. But he notes there are no guarantees when taking a patched and repaired body out on the circuit for another run.

"Hopefully there's not going to be any more injuries, but that's often the case—you come back from one injury, you're compensating, you start doing things a little different," he said. "[Maria] Sharapova had a surgery a long time ago, and she's still not quite back to where she used to be.”

As for his own return, he says patience and determination are key. "I don't really think I have much say so where my ranking is going to be or how well I'm going to be playing after these surgeries, but I would like to play as well as I can,” he says. “But right now there's not much I can do. I can't speed up the healing process. I can't make myself play better."

Alicia Molik's experience has been similar to Henin's and Clijsters', if on a smaller scale. Fed up after a string of illnesses and injuries, the Australia quit the game in 2008 but a year ago decided to return. She has worked her way through lowest levels of the Challenger circuit and is now back in the Top 100.

"Having a lot of time off, a lot of my injuries healed," Molik, 29, said. "I really wanted to step back on the professional court and join the sport again, because I was a little bit miserable when I left last time. I mean, you would be after having so many injuries. But I love the game, so 12 months ago was when I officially decided I would have a crack."

Molik spent months practicing before dipping her toe back into competition. "It was six months of hard and arduous training... It is hard. The older you get, it is more difficult on your body. But you have to put in the hours, you have to go through all the tough days and the soreness, you have to be diligent about everything. But it's something I set my mind to, its something I'm continuing to set my mind to."

It's all in search of the payoff—the big win that makes the journey worthwhile. Few comeback journeys have been longer than that of 39-year-old Kimiko Date Krumm, who ended a 12-year retirement two years ago to make it back into the Top 60. Not long after Henin marked her return in Paris on Tuesday, Date Krumm scored the biggest win of her comeback by defeating former No. 1 Dinara Safina 3-6, 6-4, 7-5 on Court Suzanne Lenglen.

A calf injury flared up mid-match, but Date still managed to come from a break down in the third set and win.

"I don't like retiring," she said, talking about the calf injury, not necessarily her 12-year break.

These days, a lot of players seem to feel the same way.