After enduring decades of flak for having no roof, now Wimbledon officials are under pressure to preserve the prestigious tournament’s century-old outdoor status.

Confusion reigned over the first week of The Championships as to when the roof should be closed.

And when it was, players moaned over the painstaking 40-minute process.

The roof closure was initially only supposed to come into effect during rain stoppages, but now fading light can also result in it being shut.

Operational since 2009, the retractable roof takes up to 10 minutes to close, during which time play is suspended, but a further half-hour delay occurs while the air conditioning system recreates an outdoor atmosphere.

Championship rules dictate that once the roof has been closed it must remain so until the end of the match, creating the possibility that matches may be completed indoors even though the sun is shining outside.

Six-times champion Roger Federer said playing indoors on grass made the tournament a lottery after he escaped from two sets down playing his third-round match against Frenchman Julien Benneteau under a closed roof.

“Shutting it creates a completely different atmosphere,” Federer said.

“I do hope we stay with an outdoor Wimbledon. I know that’s the goal of the organisers.”

Rafael Nadal was less than pleased at having to wait almost 45 minutes for the fifth set to start in his dramatic second-round loss to Czech Lukas Rosol while the roof was being shut.

After the roof was closed at one set apiece during Andy Murray’s third-round clash on Saturday night with Marcos Baghdatis, officials had to break the local council’s 11pm curfew by two minutes to usher the home hope through to the second week.

In the latest-finishing match in history at the All England Club, Murray triumphed 7-5 3-6 7-5 6-1 at 11.02pm.

The two combatants were running to the changeover towards the end to ensure the match could be completed and to save the debacle of Murray having to play on Monday, Tuesday and Wednesday to make the quarter-finals.

“Even at 5-1 (in the fourth set), the match still could have gone on. I was just lucky I finished it in a couple minutes,” Murray said.

World No.1 Novak Djokovic was also taken to four sets playing indoors in the third round against Radek Stepanek and said the different conditions.

“Look, this is an outdoor tournament, so I think everybody wants to play when the roof is open,” Djokovic said.

“I was a little bit surprised when I saw sunshine that the roof is closed.

“But obviously they’re relying on the forecast that I don’t think is very reliable here.”