Several tennis stars are expressing their anger over Maria Sharapova's positive drug test and very few are offering words of support.

Player Chris Evert claimed yesterday that no one is stepping up to support Sharapova because she has no friends in the game.

'It’s hard to tell (the reaction from players) because Maria Sharapova has always isolated herself from the rest of the tennis world, from the players. She doesn’t have a lot of close friendships on the tour,' she told ESPN.

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Better spirits: Maria Sharapova is pictured shopping in Los Angeles on Thursday after failing her drug test in January

'Honest mistake': Sharapova, 28, announced on Monday that she had been caught in a doping test after taking the drug, which became a banned substance in January

No friends: 'It’s hard to tell (the reaction from players) because Maria Sharapova has always isolated herself from the rest of the tennis world, from the players. She doesn’t have a lot of close friendships on the tour,' said player Chris Evert

'She’s made that known, she can’t be friends with the players. Her friendships are outside of the tennis world, she’s isolated herself. So it's hard.'I’m not seeing a lot of support from a lot of the players,' she continued.

Agnieszka Radwanska said she was 'shocked, like everyone else' when Maria Sharapova revealed Monday that she failed a drug test in January at the Australian Open.

'It was a very sad day for tennis, that's for sure,' Radwanska said Wednesday at BNP Paribas Open at The Indian Wells Tennis Garden.

Petra Kvitova and Simona Halep used much the same words while discussing Sharapova's positive test for the drug Meldonium.

Sharapova said she had been taking the drug since 2006 to help deal with a magnesium deficiency and other health issues, but wasn't aware the World Anti-Doping Agency had added it to the list of prohibited substances this year because she hadn't looked at the updated list.

Halep, the defending women's champion in the Indian Wells event that started Wednesday, called it 'a tough moment for the sport, a bit disappointing,' and Kvitova said 'I hope it will not affect the tennis world. I hope that the fans will still like tennis.'

Men's star Rafael Nadal termed it 'terrible for the world of sport in general and for our sport especially.'

'It's terrible because the sport must be clean and must look clean,' Nadal said.

'We have a good anti-doping program and the players who are not doing the right things are going on trial, so we will see how it goes.'

Nadal said he lets his doctor keep track of the changes on the prohibited substance list and is '100 percent confident with my team' and knows everything he is taking. But he also knows that nothing is foolproof.

Failed the test: Three of Maria Sharapova's, pictured in January, major sponsors are cutting ties with the Russian tennis star after she acknowledged failing a doping test at the Australian Open

Not happy: Simona Halep (left) called it 'a tough moment for the sport, a bit disappointing,' and Petra Kvitova said 'I hope it will not affect the tennis world. I hope that the fans will still like tennis'

Another pro: Men's star Rafael Nadal termed it 'terrible for the world of sport in general and for our sport especially.' 'It's terrible because the sport must be clean and must look clean,' Nadal said

WHAT IS MELDONIUM? Meldonium (file picture above) was a medicine Sharapova took for 10 years but it became a prohibited substance on January 1 Meldonium, also known by the commercial name Mildronate, was added to the new banned list of drugs last year, which came into place on January 1, 2016. The drug was added to the list because the World Anti-Doping Agency said there 'evidence of its use by athletes with the intention of enhancing performance.' WADA had been observing Meldonium in 2015, adding it to its 'monitoring programme' to determine its effects on athletic performance. It is used medically to treat ischemia, or a lack of blood flow. It can be used as a metabolic enhancer to increase endurance through greater blood flow. The Institute of Biochemistry - Center for Preventive Doping Research, German Sport University Cologne said of the drug: 'Anti-ischemic drug Mildronate demonstrates an increase in endurance performance of athletes, improved rehabilitation after exercise, protection against stress, and enhanced activations of central nervous system (CNS) functions.' Sharapova said she has been taking the drug since 2006 to aid in a variety of health problems. On December 22 of last year, WADA sent out an email indicating what drugs would be banned starting in 2016 and Sharapova conceded that she received but did not read that email. Advertisement

'It's difficult to imagine that something like this can happen, but there's always mistakes. Everybody can have mistakes. I want to believe that for sure it's a mistake for Maria, she didn't want to do it, but there's always (the possibility) that it's negligence.

'The rules are like this and now she must pay for it.'

Halep said she personally checks the WADA update each year and 'always when I take something I turn to the people that are taking care of this, the anti-doping, and everything is sure. If you take something you have to check very carefully before.'

Kvitova, a two-time Wimbledon champion, said: 'I think it's something which we all should know, what we are taking and what we are putting into the body,' and thinks Sharapova made 'a huge mistake.'

Radwanska called it a mistake as well, but she can understand how it happened.

'I'm scared because I know every pill can have something (prohibited) in it,' said Radwanska, who said she has been tested three times this year. 'So when I'm sick I'm just taking aspirin because I'm always afraid there's going to be something else in it (medication). '

Critical: Andy Murray, pictured today, criticized his own racket company for promising to extend its sponsorship of Maria Sharapova, despite her positive test in Australia

Kvitova said in one way the incident can be a positive for the sport because 'I think this is the kind of example that we see that they are trying to have a clean sport. I think the system is working and they are doing a good job.'

What none of them knows or would even speculate on is what penalty Sharapova might face.

The International Tennis Federation's anti-doping program regulations recommend a four-year ban if the violation was intentional and a two-year ban if it was accidental.

'For sure it's a sad day for tennis but what can I say more? We're all waiting for what they're going to do about it and that's it,' Radwanska said. 'I don't know. I have no idea what they going to do.'

Andy Murray criticized his own racket company for promising to extend its sponsorship of Maria Sharapova, despite her positive test in Australia.

Murray, preparing to compete in the BNP Paribas Open at Indian Wells, said he was puzzled why Head – whose rackets he also uses - should go out on a limb to support the Russian when so many questions were unanswered.

'I think it's a strange stance given everything that's happened the last few days,' said the world No 2.

'I think at this stage it's important to get hold of the facts and let things play out, like more information coming out before making a decision to extend the contract.

'Personally I wouldn't have responded like that.'