John McEnroe has had dealt with his fair share of controversies both on and off the court over the years.His articulate and honest commentary has been almost as entertaining as his on-court play and countless tantrums.McEnroe has again been dominating the headlines this week after claiming Serena Williams would be ranked no higher than 700 in the current men's rankings.While making that point, the winner of seven Grand Slam singles and nine doubles titles also said that she is the best female player in history.A day after making the comments to National Public Radio to promote his new book 'But Seriously', Serena Williams posted a couple of tweets urging McEnroe to stop commenting on her while she is pregnant.But when asked if he regrets what he said, in typical McEnroe style, he was not taking a backward step.Speaking to CBS, McEnroe said: "Serena is the greatest female player that ever lived."The interviewer then said why did you say woman, why don't you just say the greatest, you know, tennis player that ever lived.

"So then I felt the need, however unfortunately probably, to defend myself and just say what I really felt.

McEnroe did feel there was a way to solve any debate about the issue.

He continued: "Why don't you combine both and just solve the problem.

"I'm sure the men would be all for this — the men and women play together and then we don't have to guess.

McEnroe was apologetic for the timing of the comments and was certainly not wanting to put any undue stress on the 23-time Grand Slam winner.

Serena and Venus Williams took part in a battle of the sexes' with German player Karsten Braasch at the Australian Open in 1998.

The contest took place when the sisters claimed they could beat any male ranked outside the top 200.

Braasch who was ranked 203 at the time, took them up on the offer in a one set contest, defeated Serena 6-1 and Venus 6-2.

To be fair to the sisters, the game was when they were at the beginning of their careers and have come a long way since then.

While McEnroe went about the discussion in a clumsy fashion, it opens up a fascinating debate.

Serena has dominated the women's game for well over a decade and it would be fascinating to see how she would go against a male outside the top echelon of players.

There are undoubtedly physical barriers she would have to overcome, but it would not be the first time she has faced challenges in her life.

The other side of the debate is just to sit back and enjoy what could be the final stages of a remarkable sporting career.

It certainly has been an amazing journey.