Andy Murray last night reminded everyone just why he is one of the world's very best fighters as he scrapped his way into the semi-finals of the Sony Ericsson Open in Miami.

Struggling with what seemed like trapped wind at one stage, the Scot was in real trouble when he trailed the world No.9 Janko Tipsarevic by a set and 2-0 but battled back in typical style to claim a 4-6, 6-3, 6-4 win that will have been as satisfying as any so far this year.

In tomorrow's semi-finals, the world No.4 will take on either the world No.2 Rafael Nadal or the No.6 Jo-Wilfried Tsonga, who were due to play in the early hours of this morning.

Having rediscovered his form and confidence after an early exit in Indian Wells, the last thing Murray wanted was to let it go but when he squandered an early 4-2 lead to drop the opening set, the world No.4 was far from happy.

And when he dropped serve in the opening game of the second set, he called the doctor and told him there "was too much air in my stomach".

Whatever the pill he took was, it did the trick as he fought back from 2-0 down to 2-2 only to drop his serve once again.

Tipsarevic was taking the game to Murray, his backhand down the line particularly impressive, but once Murray got the break back in the next game, the momentum began to change.

Suddenly, Murray was pulling the trigger at the right time and covering the court better than in the first set, forcing the Serb into more errors as the match wore on. From 2-3 down he won four straight games to level the match and then broke Tipsarevic in the third game of the second set to take control.

Having held the advantage to 4-3, he saved a break point with a big ace and when he came to serve for the match two games later, he made no mistake to complete victory and take his place in the last four.

With a packed calendar from now until the US Open, Murray's confirmation that he will miss the Davis Cup clash with Belgium at the Braehead Arena next month was no surprise. The Scot believes Britain are currently at their true level.

Three grand slams, five Masters 1000 events and the Olympics are all crammed into five months so there is little room for manoeuvre and with coach Ivan Lendl also convinced Davis Cup was not the right idea this time, Murray made the obvious decision.

But it is another off-court issue that might just be competing for attention in his ever-lively mind.

At the US Open last September, Murray joined Nadal and Andy Roddick in telling tournament organisers what a farce it had become, with rain forcing yet another Monday final, thanks in part to their scheduling of the first round over three days and the outdated Saturday-Sunday finish.

Murray agrees that the players should get a bigger share of tournament revenue than they receive at grand slams, currently between 11% and 16%, which is their main issue at the moment.

With Rafael Nadal having this week confirmed that he has stepped down from the ATP Player Council, could there be a role for Murray?

It was interesting that he joined the rest of the world's top four in speaking to Phil Brook, the Wimbledon chairman, about the burning topics earlier this month in Indian Wells. Lendl would probably advise against it, but perhaps his name will find its way on to the list, to be voted on by Wimbledon this summer. Stranger things have happened.