Ivanovic to sub for Serena Williams in Garden exhibition

Serbia's struggling former No. 1 Ana Ivanovic, summoned to fill in for injured Serena Williams, called Monday night's Madison Square Garden tennis exhibition an ideal situation for testing the input of her new coach, Heinz Gunthardt.

Ivanovic, who has been in an extended slump since winning the 2008 French Open and now is ranked 23rd, announced this week that she has begun working with Gunthardt, who coached Steffi Graf in 12 of Graf's 22 major titles. During a conference call Wednesday to promote Monday night's event, Ivanovic said she already was in the midst of training in San Diego with Gunthardt in preparation for the Indian Wells, Calif., tournament that begins March 8 when she was asked to replace Williams, who cited a leg injury suffered during January's Australian Open.

"I was looking for a coach for a while," Ivanovic said. "I spoke to Heinz a few weeks ago to see if he could arrange his time to come here to San Diego. I've know him a long time; he's a great coach with a lot of experience. He makes it fun and I feel more confident about certain things and a lot more clear about things, and I hope it's going to work out in the longer run.

"Even though [the Garden event] is an exhibition, we both thought it's a great opportunity" to put their new collaboration to work. Monday's one-night mini-tournament will consist of two one-set semifinals and a best-of-three-set final. Ivanovic will play reigning U.S. Open champion Kim Clijsters in one semifinal, followed by Venus Williams against Svetlana Kuznetsova, the 2009 French champion.