Daily Bagel: Li Na, Novak Djokovic trash-talking ahead of exhibition match

http://www.youtube.com/watch?v=mtIBCgq_F_c
The Daily Bagel is your dose of the interesting reporting, writing and quipping from around the Internet.
• Video: A 12-minute video that aired on Eurosport about Serena Williams' experience at the Mouratoglou Academy. There are no subtitles for the French portions, but the footage of Serena's training sessions is worth watching.
• Li Na and Novak Djokovic have been engaging in some harmless trash-talk on Weibo in advance of their exhibition match in Beijing on Friday.
"Haha, are you ready to play me?" the Serb said on his Sina Weibo microblog.
"Don't be happy too early," Li joked. "I have a plan for the game. It is not certain who will be the winner and the loser."
• Catching up with Robin Soderling, who is going into the tennis ball business. He's designed balls that will be marketed under an "RS" label, and they've already been approved by the ITF.
“Although the fact that there are some good balls used on tour, I haven’t come across a ball like how it is supposed to be. You have heavy balls that offer more control but rather can lead to injuries and light balls that quickly fly off in all directions. Therefore it was my goal to develop control and also offers not too burdensome for your body.“
• Marin Cilic says that despite media reports and the ITF's independent tribunal report, he did not lie about a knee injury when he withdrew from Wimbledon after agreeing to a voluntary suspension due to a failed drug test.
• The Oregonian has a pretty pessimistic view as to what the tennis world will look like after Serena decides to hang up her racket.
• Taylor Townsend has split from the USTA and is now being coached by former No. 4 Zina Garrison. Townsend lost to Asia Muhammed 6-4, 4-6, 6-4 in the first round of the Party Rock Open (yes, that's still a thing).
• Maria Sharapova's former coach Thomas Hogstedt is reportedly looking to coach in South Africa.

Contributor, SI.com Nguyen is a freelance writer for SI.com, providing full coverage of professional tennis both on and off the court. Her content has become a must-read for fans and insiders to stay up-to-date with a sport that rarely rests. She has appeared on radio and TV talk shows all over the world and is one of the co-hosts of No Challenges Remaining, a weekly podcast available on iTunes. Nguyen graduated from the University of California, Irvine in 1999 and received a law degree from the University of California, Davis in 2002. She lives in the Bay Area.