Murray: Olympic field still strong

Defending champion Andy Murray insisted the Olympic tennis tournament remains a strong competition despite Stan Wawrinka joining the growing list of withdrawals.

The world No. 4 pulled out on Tuesday citing a back injury, meaning half of the men's top 10 will miss the event.

Wawrinka's Swiss teammate Roger Federer has taken the rest of the season off to recover from knee surgery, while Milos Raonic and Tomas Berdych cited concerns over the Zika virus and Dominic Thiem prioritised the ATP Tour.

Top-30 players such as Nick Kyrgios, Bernard Tomic, Richard Gasquet, John Isner, Sam Querrey and Feliciano Lopez are also absent.

Murray, who beat Novak Djokovic and Federer back to back to win gold in London, said: "It's unfortunate about Roger and Stan, they're two guys who are both great players and capable of winning events like this so it's a shame that they aren't here.

"But it's still a pretty strong field, a lot of the top-20 players are here, even if unfortunately there's a few of the top 10 missing."

Murray has not played a match since beating Raonic to win his second Wimbledon title last month.

The Scot sought final assurances from his doctor to allay concerns about the Zika virus before arriving in Rio on Monday.

Wife Kim and baby daughter Sophia will not be in Rio, although Murray insisted that was not because of health concerns and that the event had never been part of their schedule.

The 29-year-old world No. 2 said: "I spoke to my doctor and he assured me everything should be okay.

"Hopefully, I don't get too many mosquito bites, but I don't think it's too bad at this time of year and there's a lot of places that are a little bit dodgy right now, obviously the stuff in Miami, so you just hope that nothing happens."

Murray is going for doubles gold with his brother Jamie as well as bidding to successfully defend his singles title.

He frequently cites the gold medal he won in London as his favourite career moment but does not expect it to have any impact on this tournament.

"The only time when defending a title has felt a bit strange to me was at Wimbledon because you come out and open the tournament and there's quite a big thing surrounding who's playing the first match on Centre Court," he said.

"Here it's totally different conditions, different venue, different country, so I'll try and treat it like any other tournament and prepare as best I can." - PA Sport.