Tennis ‘bad boy' Nick Kyrgios has been banned for eight tournament weeks for his conduct at the Shanghai Masters last week, the governing body for men's tennis (ATP) said Monday. "The suspension will be reduced to three tournament weeks upon agreement that the player enters a plan of care under the direction of a sports psychologist ...," the ATP said in a statement. The volatile 21-year-old has also been slapped with an additional $25,000 fine for "conduct contrary to the integrity of the game", which can keep him out of action until mid-January. Tennis Australia (TA) said Kyrgios, who issued a statement Monday to apologize for his behavior, has agreed to seek professional help, which could see him return to court on Nov. 7. "Nick understands the gravity of his actions, has shown remorse and expressed a willingness to improve," TA said in a statement. "We have always offered assistance and advice to Nick and his team and will continue to do so." The talented-yet-temperamental Australian was beaten 6-3, 6-1 by Mischa Zverev in a second-round match in Shanghai in which Kyrgios put in a series of half-hearted serves and appeared to be walking off court before the unseeded German had returned the ball to him. Kyrgios also clashed with a spectator before being booed off the court. He was fined $16,500 by the ATP Thursday. ATP Executive Chairman and President Chris Kermode described Kyrgios as a "phenomenal talent" and hoped the Australian would use his time away from the game constructively. "Nick's conduct in Shanghai was unacceptable, disrespectful to the sport, and its fans," Kermode said. In his statement, Kyrgios promised to behave better when he eventually returns to the court. "Following the ATP's decision today I would like to take this opportunity to apologize again for the circumstances in Shanghai," he said. "I do understand and respect the decision by the ATP and I will use this time off to improve on and off the court. I am truly sorry and look forward to returning in 2017." Serena withdraws from Finals US superstar Serena Williams has withdrawn from the elite WTA Finals in Singapore, saying she's still working to recover from the shoulder troubles that hindered her in 2016. The WTA announced Williams' withdrawal from the event that starts on Oct. 23 on its Twitter feed, posting a video of Williams explaining the decision. It will be the second straight year that Williams is skipping the season finale in Singapore due to injury. "Hey everyone in Singapore," Williams said. "I'm really, really bummed that I won't be able to come compete this year. "It's been a really tough year for me just dealing so much with these shoulder injuries. My doctor insists that I stay home and heal it every single day." The 22-time Grand Slam champion earlier pulled out of two tournaments in China after being knocked out of the semifinals of the US Open. That defeat saw Williams' 186-week reign atop the world rankings end as Germany's Angelique Kerber reached the summit and captured the Flushing Meadows title into the bargain. Williams claimed just one Grand Slam title in 2016, at Wimbledon. After that, shoulder troubles hampered her in Rio where her hopes of a fifth Olympic gold medal were crushed in the third round. — Agencies