Madrid - Andy Murray believes negativity around the reformed Davis Cup has been unfair and is urging people to give the new competition a chance to succeed.

The inaugural Finals of the 119-year-old tournament started on Monday in Madrid, where 18 teams will now compete across the week at the Caja Magica for the chance to play in Sunday's final.

Barcelona footballer Gerard Pique has been at the heart of the changes after his marketing company Kosmos struck a $3billion deal over 25 years with the International Tennis Federation.

"I think generally people have been fairly negative about the new concepts," Murray said in a press conference on Monday.

"I just feel in tennis sometimes we are quite reluctant to make changes and this is a big change. I feel like we should give it an opportunity to see how it goes."

Participation from the game's top players had dwindled as the previous system required winning teams to play four weekends across the year.

Organisers hope the prestigious trophy can be revitalised in a more congested format, with Murray, Novak Djokovic and Rafael Nadal all in attendance this week.

"They've done a really good job with the facilities," said Murray. "The team room is really good, the food and the transport has been good. There's nothing really to complain about so far.

"It feels like there's a few people that want to bash the event before it's started. I think they have to let that go and wait for the event to finish before we give a fair view on what this event is now."

Roger Federer and Alexander Zverev are the most high-profile absentees while there are concerns too about the atmosphere at matches.

"The one concern I had, and do have, is the atmosphere in the matches in comparison to what we were used to in Davis Cup ties," Murray said.

"And until we've competed in a few matches here and felt that atmosphere, I can't say for sure what that's going to be like."

For Murray, the Davis Cup is a chance to continue his remarkable comeback from injury while also returning to team tennis, a format he has always enjoyed.

The three-time Grand Slam champion won the European Open in Antwerp last month, after undergoing hip surgery in January, when many expected him to retire following the Australian Open.

His lowly world ranking of 126 means he would have to play as Britain's number two in singles. The Scot could also be called upon to play the third and decisive doubles rubber with his brother Jamie.

"If I was asked to play doubles, I would do it," said Murray. "But maybe at the beginning of the event you have to think slightly differently than if you're in the final."

Britain open up against the Netherlands on Wednesday in Group E before playing Kazakhstan on Thursday for a place in Friday's quarter-finals.