John McEnroe was talking on BBC One's Today at Wimbledon
By John McEnroe
Three-times Wimbledon champion
Andy Murray has got to get to at least the quarter-finals at this Wimbledon, it's as simple as that.
Britain's number one Andy Murray
Murray has never reached the quarter-final of a Grand Slam tournament
He's hovered around the top 10 for a while and has looked as if he was going to make that breakthrough - but he hasn't done it yet through a combination of fitness issues, injury problems and bad luck.
I think he has to dig a bit deeper in the well if he wants to be up there with the likes of Novak Djokovic. This was a guy everybody was comparing him to a couple of years ago and who has now won the Australian Open.
They are the same age, but Djokovic has really opened up a gap on Murray.
If Murray was to get to the quarters, which he hasn't done yet at a Grand Slam, then he will have to face Rafael Nadal, presuming he can get past Richard Gasquet, a former semi-finalist.
That's not easy but it's do-able and he's got to show that he's in there with the big boys. He's been close but he's got to beat one of these guys in a big event.
Murray has to do what he's comfortable doing with his coaching (after parting company with Brad Gilbert), but the key for him is to have one ear open.
He believes in himself but he does need to listen to some people who can give him some solid advice.
The biggest thing though, is that he's got to get himself in phenomenal physical shape - better than he's ever been in.
It looks to me like he's getting better but if you really want to go deep in a major tournament then just look how hard the top guys work.
Nadal is unbelievably fit and Djokovic is the same - these guys are working harder than Murray is, in my opinion.
Roger Federer, meanwhile, was extremely sharp against Dominik Hrbaty in the first round.
Roger Federer beat Dominik Hrbaty in straight sets
Federer was back to his best at his at his favourite venue
He came out with his 'A' game from the off because he had something to prove with people starting to write him off a little bit.
Certainly there was some cause for concern after the whipping (6-1 6-3 6-0) he suffered at the hands of Nadal in the French Open final. I've never seen him beaten that badly and so thoroughly dominated.
At the same time, this is his best surface and I don't think that is the case for Nadal or Djokovic so I think things will right themselves here.
His serve is more penetrating, the ball won't get up as high on him and the way he moves about the court here is so beautiful - he's just a different guy at Wimbledon.
As for the women's top seed Ana Ivanovic, from what I saw of her match against Rossana de los Rios she was totally dominant.
She's gotten herself extremely fit and her movement is excellent. She's always been able to hit a good ball and she's learned from her mistakes.
This girl has got it all. They're going to try to market her - but it's not going to be a very difficult job! She's beautiful, a great player and seems very committed.
It's probably one of the most open women's championships in a while. The Williams sisters will step up but Ivanovic has a real chance as do six or seven of the women.