MUMBAI • Novak Djokovic's domination of tennis this year is not as inevitable as it might appear, former British No. 1 Tim Henman believes, even if the other members of the "Big Four" will have to raise their game and hope the Serb falters.
He won three of the four Grand Slams last year and has a 12-0 record this season, having thrashed Rafael Nadal, Roger Federer and Andy Murray to win the Doha and Australian Open titles.
So impressive was the 28-year-old at Melbourne Park that many pundits believe a first calendar-year Grand Slam in the men's game since Rod Laver in 1969 is on the cards.
Henman, while conceding that there is now a gap between Djokovic and the other top players, does not think it has become a gulf.
"They can definitely challenge. Murray is at the highest ranking in his career, he's No. 2 in the world. He's playing great tennis," the 41-year-old said. "Roger was in the final of the US Open and Wimbledon last year. Djokovic stopped him in his quest to win more Slams. They are still very, very close."
Henman thinks Federer, who won the last of his 17 Major titles in 2012, and Murray look most likely to prevent a Djokovic Grand Slam sweep this year, as Stan Wawrinka did at the French Open last year.
Nadal, who was knocked out in Melbourne in the first round, may not be the same player who won nine French Open titles but can still pose a serious threat on the clay courts at Roland Garros.
"The challenge for all those other players is to try and raise their levels and probably hope that Djokovic doesn't play quite as consistently," said the former world No. 4.
Tennis is reeling from revelations in a report by the BBC and BuzzFeed last month that 16 players who have been ranked in the top 50 had been repeatedly flagged to the Tennis Integrity Unit over concerns that they had thrown matches.
Henman, who was in Mumbai as the brand ambassador of the HSBC Road to Wimbledon programme, a joint initiative by the All England Lawn Tennis Club and India's tennis association, said his first reaction to the allegations was one of "surprise" and called for more proof and not just speculation.
"If there has been any match-fixing, then we need to make sure that it's erased from our sport because it's a crime in sports," he said. "It's also important to educate the young players so they appreciate this is something very, very serious if it has happened and make sure it never happens again.
"We have a Tennis Integrity Unit and if they need to invest more money in that, then we must do that."