CHARLOTTE, N.C. -- The Charlotte Bobcats said head coach Steve Clifford underwent a successful procedure Friday to have two stents placed in his heart. Bobcats president of basketball operations Rod Higgins said in a release Friday that Clifford is "resting comfortably" in the hospital but its too early to know when hell return to work. Higgins says Clifford checked himself into the hospital Thursday night because he was suffering from chest pains. Clifford, 52, joined the Bobcats this off-season after spending last year as an assistant coach with the Los Angeles Lakers. The Bobcats are off to a 3-2 start under Clifford. Hall of Famer Patrick Ewing will serve as Charlottes acting head coach against the New York Knicks Friday night. Clifford becomes the second professional coach to check himself into a Charlotte hospital in the last week. Denver Broncos coach John Fox, who used to coach the Panthers and still owns a home in Charlotte, was admitted last Saturday with chest pains after experiencing pain while on the golf course. Rookie Cody Zeller said he didnt find out Clifford was in the hospital until he reported to shoot-around on Friday morning. "I just texted him and said I was keeping him in my prayers but I dont know much past that," Zeller said. Clifford joined the Bobcats on May 29, replacing Mike Dunlap, who was fired after the Bobcats went 21-61. The Bobcats have been thrilled with Cliffords approach thus far, saying he has the right makeup to deal with professional players. He spent 13 seasons as an NBA assistant coach for the Knicks, Orlando Magic and Houston Rockets and Lakers. Ewing, the teams associate head coach, addressed the media before the game and said hes "a little nervous" about coaching his first game, particularly on such short notice. But he said his biggest concern right now is with Clifford. "Coach Clifford and I have been friends for a lot of years -- weve worked together for over 10 years now -- and this is definitely not the way I wanted to start my head coaching career with him being in the hospital," Ewing said. Ewing, a member of the Professional Basketball Hall of Fame, played 15 seasons for the Knicks from 1985-2000. The former Knick said, "Its ironic that my first chance to be a head coach will be against a team I played with for 15 years." ISTANBUL, Turkey -- Top-ranked Serena Williams overcame Agnieszka Radwanska 6-2, 6-4 for her second win in two matches at the WTA Championships on Wednesday and all but sealed a spot in the semifinals. Jelena Jankovic topped second-ranked Victoria Azarenka 6-4, 6-3 in her first match at the tournament and fourth-seeded Li Na opened her campaign with a 6-3, 7-6 (5) victory over Sara Errani. Williams cruised in the first set but ran into some trouble in the second against a player she had never lost to in seven previous matches. "She definitely played pretty well. But, you know, I can always look to improve on some things. My serve wasnt as good today as it was yesterday, but you cant expect it to be great every day," Williams said. Radwanska wasted three break points at the start of the set and dropped her serve in the fourth game. She broke right back and levelled at 3-3, but Williams pounced on her serve again in the final game, winning the match with a backhand winner. Radwanska has won just one set of 17 she has played against Williams overall - in the 2012 Wimledon final. She has now dropped both round-robin matches in Istanbul, where she also lost to Williams in last years semifinals. Williams is bidding for her fourth title in the event. Errani also lost her opening group match on Tuesday to Azarenka and now looks all but certain to be eliminated. Jankovic, who was ranked No. 1 in 2008 and is back in the top 10 for the first time since 2011, outplayed Azeranka to snap a four-match losing streak against a fellow former No. 1. "Vika is a great champion, and I knew it was going to be a tough match. We played against each other in Cincinnati and I lost in three sets, and I think the difference today was that I was serving much better," Jankovic said. Williams, 32, is enjoying the finest season in her career, having already won 10 titles. She added the French Open and U.S. Open titles to bring her Grand Slam record to 17 championships and is 75-4 for the year. Williams, making her eighth appearance in the event, is looking to become the first player to successfully defend the title since Justine Henin in 2007. Henin was also the last to win 10 titles in a season, in 2007. Williams has clinched the year-end No. 1 ranking for the third time in her career after 2002 and 2009 Li trailed 3-1 in the second set against Errani, but won the next four games.dddddddddddd She twice attempted to serve for the match, first, wasting a match point at 5-3 and then again at 6-5. Despite trailing 3-1 in the tiebreaker, Li won the next five points and eventually converted her third match point when Errani sent a forehand into the net. That saw her take her head-to-head meetings against her Errani up to six wins without defeat. "The first match is always tight," Li said, adding that she had felt rusty after a three-week break since her last tournament. "I still have to find the rhythm on the court." The tournament brings together the top eight players in the world. They play two round-robin groups, with the top two finishers in each advancing to the semifinals. Jankovic, now ranked No. 8 and seeded seventh because third-ranked Maria Sharapova pulled out of the event with a shoulder injury, proved to be the steadier player against Azarenka, the Australian Open champion. "I was able to hold my serve and stay focused when I was serving and I waited for my chances to break, and she made some double faults at times and I took advantage of that," Jankovic said. "Its a great win for me, it gave me a lot of confidence." The key game in the first set went to Jankovic after more than 10 minutes when she held serve for a 5-3 lead. Azarenka saved two set points in the next game but then sent a forehand wide on Jankovics fourth in the 10th game. Azarenka dropped her serve in the third game to fall behind and then held in the fifth despite serving three double-faults and facing four break points. But she could not trouble Jankovic on her serve and another forehand by Azarenka that sailed long to hand Jankovic the match. "Of course she was playing well. I mean, I think shes playing her best tennis right now. Really improved a lot throughout the year, " Azarenka said. "But I cannot say that I played well and she was better today. Of course she was better today, but, you know, I let a lot of balls go. There were a lot of mistakes, small mistakes, a little bit bigger mistakes." After losing the U.S. Open final to Serena Williams, Azarenka lost her opening matches in both Tokyo and Beijing before beating Errani on Tuesday. Azarenka still has a 5-4 career edge over Jankovic. 16:56ET 23-10-13 wholesale Jerseys wholesale nfl Jerseys china Jerseys from china nfl Jerseys cheap authentic Cheap Jerseys ' ' '