ANDY Murray and Novak Djokovic sometimes seem as if they have been shadow boxing since they emerged from the womb, within a week of each other, in Glasgow and Belgrade in May 1987. The peaks and troughs in their 31 see-sawing career meetings take some believing.

While the Serb now holds the whip hand with 22 wins, including four Grand Slam finals, he has also presented Murray with both of his major wins to date.

And just when you thought it was impossible, the relationship entered a new phase. For the next few weeks they will enter a blinking contest as they attempt to marshal their finite resources of energy and work out where a Davis Cup tie between Great Britain and Serbia fits into a six-month period in which three Grand Slam titles are up for grabs, not to mention an Olympic crown which Murray longs to keep hold of and Djokovic desperately wants to prise from his possession.

The tie, where Britain are the visiting team, will be played in mid-July immediately after Wimbledon, at a time when the equilibrium between the two men may have shifted yet again. While both showed admirable commitment to a competition they already have on their resume - Djokovic in 2010, Murray in 2015 - by grafting for just shy of five hours on Sunday against Kei Nishikori and Mikhail Kukushkin respectively, Murray has made the opening gambit in this particular chess match. The Scot's love for the team version of the sport stems from his childhood and he restated his commitment, if fit, to continue defending Britain's Davis Cup crown come July early in the weekend. Whether Djokovic has the same appetite when push comes to shove remains to be seen.

"It is incredible he has committed again this year to every tie, it sums him up," said Smith. "He will do virtually anything to get a point for the team. From a very young age, he and Jamie, and their mum Judy, they really embraced the team elements, whether it was club tennis, county tennis, regional tennis, then into international. That has never really gone away."

Murray feels he can spread himself around the calendar's various competitions, even if it means tempering expectations slightly. "I think you can focus on all of them but you also have to be realistic about your performance in all of them," said the World No 2. "You are unlikely to play your best in all of them and physically you are unlikely to feel perfect during all of them. Wimbledon should be fine and the Davis Cup, but it is the accumulation of weeks and matches that you play, so that by the Olympics and the US Open I would imagine you start to feel fatigued. That is why you have to be forward thinking and planning days off in advance."

There is a danger of falling into the one-man team trap, of course, with Jamie Murray - and Serbia's big-serving doubles specialist Nenad Zimonjic - also hopeful of a long run on the grass of Wimbledon. Kyle Edmund was excused cheerleading duty this weekend to fly out to Indian Wells and there could even be Aljaz Bedene to factor in, a native countryman of Djokovic's from the former Yugoslavia, albeit the Slovenian part, who could yet become available for the British No 2 singles slot by the time the tie ticks round, with his latest hearing on his conversion to British nationality being heard on March 20. “If he becomes available, it's another high-quality player that we've got at our disposal," said Smith. "Fingers crossed it goes his way."

How much of a step-up Serbia represents is a moot point, considering Britain overcame a French team featuring three top 20 talents during 2015, but Smith admits the choice of surface for the tie - which must come by early April - will be fascinating. While the Serbs could try to discomfort the Scot to the maximum by playing the tie on clay, an early transition to hard court would be more kind to Djokovic's Olympic preparation. "I guess it depends if Novak plays or not," said Smith. "If he plays then I guess they'll have to have quite a big conversation with him about going grass, clay and then onto hard court immediately.”

Smith remained unsure last night whether Murray's commitment to the tie had forced Djokovic's hand. "To pack in an Olympics and a Davis Cup is something very different to what he [Djokovic] is used to, it depends what his mindset is on that," he said.

But his main focus is Murray and keeping him productive and focused against Nishikori was another lesson in understatement. "It is a privilege to sit with him in that chair, as much as it might seem stressful," said Smith. "He looks so angry at times but he is not, once he gets it out his system he actually becomes quite focused quite quickly. Someone with his quality and his experience knows all the answers - it is just a question of getting some dialogue going so he can get to that point where he works out the next stage."