Manchester United are facing further defensive problems, with an injury to Ashley Young prompting a possible move into the January transfer market for manager Louis van Gaal.

Young is to undergo groin surgery after suffering an injury during United's 1-0 win at Liverpool last Sunday.

Pep Guardiola enters the final four months of his three-year reign as Bayern Munich coach on Friday with the Spaniard under pressure to sign off with the treble.

Bayern kick-off the second-half of the season at Hamburg with an eight point lead in the table and if things continue Guardiola will end the Bundesliga season on May 14 with the Bavarians having become the first club to win the German league title four times in a row.

Roger Federer was already a long way clear at the top of the list of men with the most wins in Grand Slam singles matches, so becoming the first to 300 almost seemed like a secondary consideration.

He reached the milestone at Rod Laver Arena on Friday, when he moved into the fourth round of the Australian Open with a 6-4, 3-6, 6-1, 6-4 victory over Grigor Dimitrov.

The International Olympic Committee says the new stadium for Tokyo 2020 will be completed two months earlier than planned to allow organizers time to stage more test events before the games.

Japanese organizers told IOC vice president John Coates during a two-day IOC "project review" that the completion date would be moved from January 2020 to November 2019.

Maria Sharapova reached a career milestone on Friday, which came as a nice surprise after a tough match.

"Oh, wow. I've won 600 matches?" Sharapova said, when an on-court interviewer congratulated her for the achievement earned by winning her third-round match Friday at the Australian Open.The No. 5-seeded player then thought a moment, and laughed nervously.

Kei Nishikori came to the Australian Open this year hoping to put his injury-ravaged 2015 season behind him.

Just five matches into the season, though, spectators at Margaret Court Arena cringed at a familiar sight on Friday: Nishikori plopped down in his chair during a changeover, grabbed his heavily taped right wrist and called for the trainer.

Bayern Munich coach Pep Guardiola admits he is unsure of his team's form ahead of Friday's Bundesliga match at Hamburg in the wake of their shock defeat at Karlsruhe.

Bayern lost 2-1 at second division Karlsruhe last Saturday in their final warm-up before facing Hamburg away in the first German league match of 2016.

Former world number one Lleyton Hewitt bade an emotional farewell from tennis on Thursday after a combustible Australian Open defeat in which he was warned for swearing and slammed the umpire as an "idiot".

The intensely competitive Australian, roared on by a partisan crowd, couldn't live with Spain's David Ferrer and he went down 6-2, 6-4, 6-4 to exit what was his final tournament before retiring.

Andy Murray seized on a crucial psychological edge before dismantling Sam Groth, the holder of the world's fastest serve, as he swept into the Australian Open third round on Thursday.

In the locker-room before the match, the wily Scot overheard Australia's Groth saying he was playing at Rod Laver Arena, with all the pressures of a big home crowd, for the first time.

Holders Barcelona overcame the absence of Lionel Messi and Luis Suarez to take a huge step towards the Copa del Rey semi-finals with a 2-1 win at Athletic Bilbao on Wednesday.

Messi was absent due to a hamstring problem, whilst Suarez completed a two-game Cup ban, but the visitors still took control of the tie with two goals in six first-half minutes from Munir El Haddadi and Neymar.