Sports Shorts: Injured Li Na to miss US Open

World No 2 Li Na of China has been ruled out of this year's US Open with a knee injury.

Li, 32, who won the Australian Open earlier this year for her second Grand Slam title, has targeted a return to action in late September.

The BBC quoted her, as saying on a Facebook post that she had been struggling with her injured knee since March this year, and that she felt that it was not in order for her to play at the highest level.

The US Open starts on 25 August in New York and Li will miss the WTA events in Montreal and Cincinnati as well.

Li said that her medical team has advised her to take some time off to rest her knee.

- NEXT: Muhammad Ali's gloves worth $400,000!

The gloves that boxing great Muhammad Ali wore in his legendary 1971 fight against Joe Frazier in what became known as the Fight of the Century sold at auction on Thursday for almost $400,000.

An anonymous bidder bought the gloves for $388,375 at the auction run by Texas-based Heritage Auctions at the National Sports Collectors Convention in Cleveland. Heritage previously auctioned a set of gloves Ali wore to claim his first World Championship in 1964 for $836,500.

The Fight of the Century, in New York's MadisonSquareGarden, was the first of three fights between Ali and Frazier during the 1970s.

In 1971, Frazier officially held the title of Heavyweight Champion of the World. Ali had been stripped of the title he had held since the 1964 bout against Sonny Liston because of his refusal to participate in the Vietnam War-era draft.

The March 8 fight against Frazier was Ali's second after returning to the ring following a 3-1/2 year absence. Ali's conviction had just been overturned earlier in 1971 by the U.S. Supreme Court and his boxing license was reinstated.

"It was a controversial fight at a controversial time in America and the bout took on distinctly political and cultural overtones," Chris Ivy, director of sports auctions for Heritage, said in a statement.

Frazier and Ali were each guaranteed $2.5 million, a record purse for the time.

- NEXT: 'Drogba still has killer instinct'

Veteran striker Didier Drogba will still strike fear into defenders when he begins his second spell at Chelsea, manager Jose Mourinho said on Friday.

"The killer instinct is still there," Mourinho, in an interview with Sky Sports, said of the 36-year-old Ivorian who signed a 12-month contract last month after spells in China and at Turkish club Galatasaray since leaving StamfordBridge following the Champion League final victory in 2012.

Drogba will give Mourinho a tried and tested formula in attack, where he will be vying for a place with Spanish duo Fernando Torres and new signing Diego Costa.

"He still has the technique to score goals and the physical strength and presence is still the same," Mourinho, who signed Drogba from Marseilles in 2004, said.

"Mentally he is the same. Every training exercise, his desire to compete and to win is always there.

"He will be an important player for us."

Almost unstoppable at times with his pace, power and strength, Drogba wrote his name into Chelsea folklore during his first spell at the club, scoring 157 goals and helping the club to the Premier League title in 2005, 2006 and 2010.

He also lifted the FA Cup four times and the League Cup twice.

- NEXT: Steve slays Karlovic in Washington tennis

Steve Johnson pulled off another upset over one of the circuit's big men at the Citi Open in Washington on Thursday, ousting towering ninth seed Ivo Karlovic 3-6, 7-6, 7-6, while top-seeded Czech Tomas Berdych was also eliminated in the third round.

Johnson, who disposed of lofty fellow American and fifth seed John Isner on Wednesday, saved two match points against the 6ft-11in (2.11m) Karlovic and withstood a barrage of 27 aces to seal victory over the Croat in a third-set tie-breaker.

Wild card Berdych was broken four times as he succumbed to 24-year-old Canadian Vasek Pospisil 6-2, 6-4 in only 81 minutes in the evening session at the WilliamH.G.FitzgeraldTennisCenter.

Pospisil, who teamed up with American Jack Sock to win this year's Wimbledon men's doubles crown, booked his place in the last eight where he will face Santiago Giraldo of Colombia, a 6-2, 6-0 winner over Victor Estrella of Dominican Republic.

Also going through to the quarter-finals on Thursday was big-serving Canadian Milos Raonic, who overpowered veteran Australian Lleyton Hewitt 7-6, 7-6 in a match where neither player had their serve broken.

Raonic, the second seed, won 72 percent of the points on his serve while firing down 29 aces as he triumphed after a tightly contested encounter lasting a little less than two hours.

World number seven Raonic will take on Johnson in the quarter-finals.

In other matches, fourth-seeded Japanese Kei Nishikori beat Slovalia's Lukas Lacko 6-2, 2-6, 6-3, sixth seed Richard Gasquet of France crushed American Tim Smyczek 6-3 6-2 and big-serving South African Kevin Anderson eased past Tunisia's Malek Jaziri 6-,3 6-4.

In the women's competition, second-seeded Russian Ekaterina Makarova brushed aside American Lauren Davis 6-2, 6-4 in the second round and fifth seed Anastasia Pavlyuchenkova of Russia eased past Japan's Hiroko Kuwata 6-3, 6-3.

- NEXT: Expect fight, says Mourinho

Petr Cech is ready to take up the challenge of competing with Thibaut Courtois for the position of Chelsea's number one goalkeeper, manager Jose Mourinho said on Thursday.

Belgian international Courtois, 22, has returned to his parent club following a long-term loan spell with La Liga champions Atletico Madrid and will battle with the Czech keeper for the starting role at Stamford Bridge.

Cech, 32, who has been Chelsea's number one for the past decade, is back from the dislocated shoulder he suffered in May and has featured in the pre-season games.

"Petr is working hard, he recovered in almost record time from his surgery and he's ready to fight for his position," Mourinho told Sky Sports television.

"Thibaut has just arrived...as the best young goalkeeper in the world, and they will fight. For me this is a good problem and I've never been afraid of making a decision.

"I prefer to be in this position than not to have good goalkeepers for Chelsea. To have Petr and Thibaut together in the same squad is a good problem for me," said Mourinho.

"This is a club that wants to be strong and have real possibilities to compete for trophies so we need competition in every place."

- NEXT: Villa vows to add to legacy in New York

For Spanish striker David Villa, the chance to start afresh in Major League Soccer with New York City at Yankee Stadium proved irresistible in his quest to add to his legacy.

Villa, Spain's all-time top scorer, last month became the first player signed by New York City FC, co-owned by ManchesterCity and the New York Yankees, who will debut in 2015.

"Being in New York City, being there in the beginning as a founding member, being the first guy, those were all factors," Villa, 32, said through an interpreter on Thursday at Macombs Dam Park across the street from the stadium.

Villa, who played at three World Cups including Spain's 2010 triumph and was at Spanish giants Barcelona before moving to Atletico Madrid and helping them win the Spanish league last year, said he liked the idea of building something new.

"I’ve done a lot over there (Spain), but once I heard the vision and everything (here), I was on board and wanted to be a part of it," said the bearded Villa, diamond studs glittering in each ear, after a Q & A with players at a youth tournament.

"I've done a lot already in Europe, a very, very good career. An opportunity to start from zero and start all over again is something that I thought was exciting," he said.

Villa was soon joined at the New York club by England and former Chelsea midfielder Frank Lampard, which has added to the Spaniard's excitement.

"He’s a legend. He’s one of the greatest," Villa said.

"The opportunities will be great and I'm excited to see what we can do together."