SAN JOSE, California - World No.15 Elise Mertens has hired Dieter Kindlmann as her new coach ahead of the North American hardcourt season. Mertens was previously coached by Rick Vleeshouvers. Kindlmann will be Mertens' third coach of 2018, a season that has been a remarkable breakthrough for the 22-year-old Belgian. 

"We started working together since last week," Mertens told WTA Insider ahead of the Mubadala Silicon Valley Classic, where she is the No.4 seed. "Since then, we worked on some stuff, but of course I see the bigger picture. It's going to be really exciting. This will be our first tournament together."

"Dieter is very experienced. I think he's a really great coach. We understand each other on and off the court."

Kindlmann, who served as Maria Sharapova's long-time hitting partner, has coached Anastasia Pavlyuchenkova, Laura Robson, and most recently Madison Keys, helping the American make her first Slam final last fall at the US Open. Keys and Kindlmann split in May before her run to the semifinals at Roland Garros. 

Mertens has seen her ranking rise quickly over the last three seasons. She began the 2017 season ranked No.120 and finished ranked No.35 after winning her first WTA title in Hobart. She began 2018 on a 9-match win-streak, defending her title in Hobart before making her first Slam semifinal at the Australian Open. 

"It was going really fast so far since my first WTA title," Mertens told reporters. "It only went upwards, better and better. I think after Australia I realized that I had it in me. You always have to believe in yourself. Sometimes it's more difficult than others. But I believe I can do great stuff and go upwards."

Mertens sits second behind Petra Kvitova in titles won this season (3) and currently sits at No.11 on the Porsche Race to Singapore Leaderboard, putting her in contention to qualify for her first BNP Paribas WTA Finals Singapore presented by SC Global. She's also at No.10 on the Porsche Race to Singapore Doubles Leaderboard with her partner Demi Schuurs.It's been an outstanding year for Mertens. But she's hungry for more. 

"I think it was time for a change because you need somebody who has the experience already," Mertens said. "I'm ranked No.15 and I'm trying to go upwards and I think he's a person who can help me."

Mertens is making her tournament debut at the Mubadala Silicon Valley Classic this year. She plays either Alison Riske or Ashley Kratzer in the second round and could face Serena Williams or Johanna Konta in the third round. "It's good preparation for the US Open swing," Mertens said. "You have to get a lot of matches in your legs on hard courts. It's good to get started already."

As for her goals for the remainder of the season, Mertens said she's more concerned with her level than the number next to her name. 

"I don't like to make goals rankings-wise, I like to put it more level-wise and try to play better against the top players. That's something I want to improve. I played Halep twice and she was just too good for me. But I want to improve that, the Top 10 players, play more against them, and get farther in these tournaments."