NEW YORK (Reuters) - A former construction worker is helping some of the world's best tennis players, including world number two Caroline Wozniacki, with an innovative "a la carte" coaching program.
Sven Groeneveld, who quit his studies at the University of Kansas to work on a building site, has gone on to become one of the world's best-known coaches, working with the likes of 1991 Wimbledon winner Michael Stich and former U.S. Open finalist Greg Rusedski.
But for the last four years, the Dutchman has been heading up the Adidas player development program.
The idea was set up, as Groeneveld says, to give players sponsored by the brand "additional advice, coaching and motivation."
"We're not a McDonald's drive-through, more like a Michelin-starred restaurant," explained the Dutchman at Flushing Meadows. "It's like picking off an a la carte menu."
The scheme is a free, voluntary service offered to the entire stable of Adidas players, who can use it as much or as little as they want.
Groeneveld and his team have previously helped Ana Ivanovic to the world number one spot as well as turning Spain's Fernando Verdasco into a genuine contender in the majors.
But over the last two years the player he has worked most closely with is Denmark's Wozniacki, who was surprisingly knocked out of the women's U.S. Open in Friday's semi-final by Russia's Vera Zvonareva.
Wozniacki, who is also coached by her father Piotr, has credited the Adidas program with helping her move toward the top in women's tennis.
Groeneveld was originally the sole coach working on the Adidas project but, because of its popularity, other big names have been recruited to make it a four-man team.
The others are Andre Agassi's former coach Darren Cahill, trainer Gil Reyes, and Mats Merkel, a qualified coach and now a hitting partner to some of the world's top players.
Between the four they boast more than 100 years experience in tennis coaching.
"There's not an unlimited budget so we're probably going to stick with that number for now," said Groeneveld.
"But we're basically on hand at the big tournaments to offer whatever help we can. That can be coaching, just a talk or in the case of Fernando Verdasco here, we had to help him get some more shirts."
Editing by Steve Ginsburg