ANDY Murray admits Wimbledon's top contenders have been put on high alert after two-time champion Rafael Nadal's shock second-round exit.
Murray was on course to face Nadal in the quarter-finals at SW19 but the Spaniard crashed out in four sets to world number 102 Dustin Brown on Thursday night.
It means the draw has opened up for the British number one after eighth seed David Ferrer, also placed in Murray's quarter, withdrew from the tournament through injury.
Murray plays Italian Andreas Seppi for a place in the last 16 on Saturday and the Scot insists Nadal's defeat proves nothing can be taken for granted.
"When that happens it's always a bit of a warning to everyone else," Murray told Press Association Sport.
"The depth of tennis just now is very high and upsets happen, and for sure they happen more than they did a few years ago."
Murray's consistency against lesser opponents is impressive given the 28-year-old has reached 17 consecutive grand slam quarter-finals.
He will be confident of avoiding an upset against Seppi too, after winning their last six encounters without even dropping a set.
"I expect a tough match," Murray said. "He made the final in Halle two weeks ago and he beat Roger (Federer) in Australia, so he's a very dangerous opponent.
"It's going to be an extremely difficult match to win."
Murray was left unsatisfied by a battling first-round victory against Mikhail Kukushkin but the world number three showed his class against Robin Haase, ousting the Dutchman with his variety and speed of thought.
A more dominant, aggressive style of play has been high on Murray's agenda this year and crucial to that adjustment has been new coach Jonas Bjorkman.
Bjorkman, who reached a career-high ranking of four in the world, joined Amelie Mauresmo on Murray's back-room team in March and Tim Henman believes the Swede will prove an excellent addition.
"I know Jonas very well, I played 10 years at least on the tour with him, we practised together a lot and he's a great guy," Henman told Press Association Sport.
"I think he will have a very positive impact, and he'll have more and more responsibility with Amelie Mauresmo's pregnancy.
"You talk about someone getting the maximum out of their game, he was limited but he made it to four in the world.
"He knew exactly what to do to make sure he went absolutely as far as he could in the game.
"And that kind of depth of analysis and work ethic will definitely translate into making him a good coach.
"So you've got Jonas who squeezed absolutely everything out of his ability in his career, and when you've got the tools of Murray's trade as well, to use those in the right fashion, I think it's a great combination."
Former British number one Henman backed Bjorkman's calm attitude to help Murray continue to keep a lid on the frustrations that can build when the grand slam course does not run smooth.
"Jonas had a great attitude in his playing days, he worked extremely hard and really enjoyed the whole process," said Henman.
"And I think that's absolutely spot-on for Andy on the mental side of things, to get out there and have fun, and to really enjoy the process of what he's working on and the way that he plays.
"And it's about not getting frustrated with himself; to really be clear in the process not the outcome. So I think that's working well."
