Maria Sharapova and her positive drugs test. What we saw yesterday was textbook PR from sport's richest woman.

Front-foot the issue, own it, say sorry. And hope that after the initial storm it will go away.

It won't. It's too big.

And Sharapova's excuses -- enveloped in a healthy dose of arrogance -- are paper-thin.

She lives in the States and this drug isn't approved for use there. You can't get it in the US -- but this is what I've been reading this morning. It is one of Latvia's most exported products and you can get it in the surrounding countries too -- Russia, Ukraine, Moldova, Belarus, Azerbaijan and Armenia.

WADA - the World Anti-Doping Authority was monitoring it, then when it discovered a number of high performance athletes were taking it, it went on the banned list.

Sharapova said she didn't realise it had become a banned drug. That is a remarkable show of ignorance on her part. She earns $30 million a year, largely in endorsements. To suggest you would put all of that at risk by not looking at the updated banned drugs list when its sent through from WADA - well, that's farcical.

She also says she still seeks the advice of a family doctor in Russia. Again, that's hard to believe. She would have a high performance team of people around her -- doctors, health experts, physios, sports psychologists, you name it. If you're the highest paid and arguably the most recognised female athlete on the planet – you give the old family GP the heave-ho and partly for this very reason. You tap into high performance specialists.

Nike has suspended her endorsement contract. So too has Tag Heuer and Porsche. More will likely follow.

And now this five-times grand slam champion is facing up to a four year ban. Russian Olympic authorities say it's an honest mistake -- they want Sharapova to play at the Olympics this year. But I can't see how that can happen.

If Sharapova wants to prove her innocence, then it's simple -- she has to provide diagnostic evidence that she has a condition that required a meldonium prescription.

If she can't do that, her whole reasoning goes out the door. There is no other option then to ban her.

It's a sorry, sorry end to what was a pretty remarkable career.