Sydney FC chief executive Tony Pignata has denied claims that former Juventus star Alessandro Del Piero is unhappy and will leave the A-League during his second season.

There has been media speculation that Del Piero won't continue with Sydney next year and that he might even seek a new club as soon as the January transfer window opens.

In a dramatic climax to one of the tightest groups in Champions League history, Borussia Dortmund needed an 87th-minute goal at Marseille to advance at the expense of Napoli which beat Arsenal.

Dortmund, last season's beaten finalist, was on the brink of elimination and missed a series of chances against the 10-man French side until Kevin Grosskreutz scored to clinch a 2-1 win.

Three Ajax fans were taken to hospital after being stabbed in the buildup to the Dutch club's Champions League match at AC Milan on Wednesday, Italian media reported.

ANSA news agency said that one fan is seriously injured after being stabbed in the abdomen and was undergoing surgery, while another was wounded in the buttocks after also being attacked by Milan ultras. The third was stabbed in the thigh. All of them have been taken to different hospitals in the city.

Wesley Sneijder scored a late goal Wednesday to help Galatasaray advance to the knockout stage of the Champions League with a 1-0 win over Juventus in a weather-delayed match.

The former Inter Milan midfielder scored in the 85th minute in snowy conditions, eliminating Juventus from the competition.

Japanese tennis star Kei Nishikori has enlisted the help of Michael Chang as he looks to break into the top 10 in 2014.

Chang will join Nishikori's coaching staff for 17-20 weeks in 2014, Nishikori's management team announced on Wednesday.

Germany defender Jerome Boateng has extended his contract with Bayern Munich in a deal that will keep him at the Champions League titleholder through mid-2018.

The Bundesliga champion's chairman, Karl-Heinz Rummenigge, said Boateng has become one of the club's "important players" and that it was only "logical" for Bayern to seek to keep him.

Indiana showed it is a legitimate challenger to Miami for the NBA Eastern Conference crown by beating the Heat 90-84 on Tuesday, pulling off an impressive second-half rally in a clash of the East's top two teams.

Among the day's other games, Oklahoma City made it 11 wins from 12 games by beating Atlanta, San Antonio recovered from a big early deficit to run down Toronto, and Phoenix was too good for the Los Angeles Lakers even with Kobe Bryant getting back near his old self.

It's a good thing the mayor of World Cup city Manaus has a sense of humor. Because some of the stuff being said of late about this historic city deep in the heart of the Amazon jungle is laughable.

Last week, it was England coach Roy Hodgson, expressing misgivings about the city's taxing high heat and humidity.

Indian athletes have been cleared to compete in the Winter Games in Sochi after the country complied with the IOC's ethics rules and avoided becoming the first country expelled from the Olympics in more than 40 years.

Still to be determined is whether the few Indian athletes who have qualified for Sochi compete for their country or under the Olympic flag.

Olympiakos and Bayer Leverkusen reached the last 16 of the Champions League on Tuesday, with either Juventus or Galatasaray set to join them after their match in Istanbul was abandoned because of a snowstorm.

Match officials stopped play after 31 minutes, ruling the field was too dangerous to play on. The last hour will now be played on Wednesday, kicking off at 3pm local time (1300 GMT).