ONCE envisaged as a death struggle between the world's two top players, Great Britain's Davis Cup quarter-final against Serbia now seems fated to be the unlikely first leg of Andy Murray's celebration tour or else a clash of the nation's respective B teams.

The withdrawal of the Balkan nation's top two singles players, Novak Djokovic and Viktor Troicki, lends this tie a wholly different complexion to when it was first drawn, but assuming the world No 2 doesn't follow suit in the next 48 hours then where better than Belgrade in July to arrive with the Davis Cup trophy and the Wimbledon singles trophy in your hand luggage?

While Murray is otherwise occupied taking on Milos Raonic - the naturalised Canadian who was born in Podgorica in nearby Montenegro - Leon Smith and the rest of the Davis Cup squad fly out from Heathrow to Belgrade today. While Murray still may make the decision to withdraw to ward off exhaustion ahead of the hard court challenges at the Olympics and the US Open, the 29-year-old enjoys these events and has been adamant he will play in the match "if fit".

While Davis Cup play tends to be unpredictable, the Scot confirming his availability would make Britain short price favourites to host a Davis Cup semi-final against Argentina or Italy, quite possibly back in Glasgow, in September.

Smith named an orthodox first selection of Andy and Jamie Murray, Kyle Edmund and Dan Evans - with Dom Inglot also travelling - but has already begun to hedge his bets. James Ward has been drafted in as cover for Evans, who progressed through two rounds at SW19 before falling to Roger Federer but has undergone an MRI scan since then on an injured shoulder. Two members of the line-up can be changed at any point up till Thursday's draw but it seems unlikely that the British team will turn up to find Djokovic or Troicki have been parachuted back into the line-up.

If Smith has dilemmas to confront, so too does his counterpart Bogdan Obradovic. Instead of the world No 1 and world No 27, he is now limited to Dusan Lajovic (82), Filip Krajinovic (108) and the veterans Janko Tipsarevic (411) and Nenad Zimonjic, the doubles expert who is now 40.

Things could be worse, though. Tipsarevic has previously been a top 10 player while Lajovic, a veteran of two live rubbers in the 2013 Davis Cup final, is unlikely to be overawed by playing in front of a passionate home support at the Tasmajdan Stadium.

For his part, Troicki would be surprised if Murray makes himself available after everything that has gone on.

"We will see if Andy will play but it is going to be tough for him also, right after Wimbledon, particularly with him getting to the final," said Troicki. "It is going to be tough for him changing the surface to clay then after that going back to hard. So I would be surprised if Andy plays in this match, because it is a tough trip and everything is tied together on the schedule.

"Normally all the spectators would be looking forward to Novak and Andy. We will see what the tie is going to look like, and who is going to show up but it is still an interesting match. We still have the players for that tie on clay so I hope they will try their best and win that match."

Lajovic lost both those Davis Cup final rubbers, against Tomas Berdych and Radek Stepanek, but still drew plaudits from his countryman Djokovic. Serbia, who overcame Kazakhstan to get this far while Great Britain were taking care of Japan in Birmingham, took the title itself in 2010.

"We will make our decision once we see how everyone is playing, and it also depends if Murray is playing," said Lajovic. "It will be different for us without our top two players but we still have a good chance. It is going to be a good tie, and a good match, a good chance for us to play some good tennis in front of a good crowd. Andy playing would change things a lot but I will hope we will win."

Meetings between the world's top players on Davis Cup duty are rare, although Murray and Djokovic did have a near miss when these two teams last met at the Braehead Arena in 2006. Djokovic won two singles rubbers that weekend, with Ilija Bozoljac and Nenad Zimonjic winning the doubles against Andy Murray and Greg Rusedski. Smith expects a difficult tie no matter what. "In the last match Djokovic played [Mikhail] Kukushkin and everyone said that’s a weak match on paper," said Smith. "It doesn’t turn out like that in Davis Cup. It’s going to be very, very hot, 35 degrees plus. It’s on clay, their chosen surface. Their home fans. They will be lifted to play against the defending champions. It’s going to be very difficult whoever turns out for them."