ANDY MURRAY will dig deep for "one more big push" as he attempts to continue the best season of his career by guiding Great Britain to a second consecutive Davis Cup final.

Britain's run to a first title in 79 years last November had seasoned observers rubbing their eyes in disbelief, and a second straight crown is a distinct possibility.

Leon Smith's team go into this weekend's semi-final against Argentina at Glasgow's Emirates Arena as warm favourites to move through to a November clash with either France or Croatia.

Much will, of course, depend on Murray, who is again likely to play singles and doubles with his brother Jamie but looked distinctly weary on the practice court at the end of a gruelling summer.

The world number two doubled over to catch his breath on several occasions during a practice set with Dan Evans.

Murray said: "I took a few days off after New York and came here and I've been practising since Sunday. I get a little break after I'm finished here so one more big push this weekend.

"At the end of last year, Davis Cup for all of us was a priority but I don't think at the beginning of the year we expected to win the event.

"But as you get closer and closer you want to make the most of the opportunity and we want to do it again this year if possible. It's going to be hard and I want to win all the events I can.

"It's been the best year of my career so far and I hope I can keep it going."

Murray saw a run of seven consecutive finals taking in a second Wimbledon title and Olympic gold medal come to an end with a quarter-final defeat by Kei Nishikori at the US Open last week.

He betrayed his physical and mental fatigue by allowing himself to become irritated by a loud noise that interrupted a key point when he appeared in control of the match.

The 29-year-old will need to avoid such distractions in what could be the key rubber of the tie against Juan Martin Del Potro.

The pair played each other virtually to a standstill in a titanic battle for Olympic gold last month, and Del Potro backed that up by reaching the US Open quarter-finals.

Murray said: "It will be a tough match. He's one of the best players in the world when he's fit and healthy and he's played really well over the last couple of months. He's very solid, a good ball striker and he doesn't mind playing indoors."

The big question is whether the match will come on Friday or Sunday.

Although Del Potro is Argentina's best player, his ranking is still recovering from the two years he spent away from the game undergoing three wrist operations and both Federico Delbonis and Guido Pella are ranked above him.

Friday's singles rubbers pit the respective number one and number two-ranked players from each country against each other, with the number ones doing battle first up on Sunday.

Argentina captain Daniel Orsanic has several options and, although he has decided on his team, he will not reveal it until the draw on Thursday.

Murray insisted the uncertainty will not affect him, saying: "Tomorrow we'll find out and I'll get ready to play whoever it is on Friday but it doesn't matter to me who plays the first day."

While Orsanic has made up his mind, Smith is still mulling over who to pick as his second singles player.

Both Kyle Edmund and Evans have presented very strong cases. Edmund stepped up impressively in Murray's absence from the team for the quarter-final in Serbia in July, winning both his singles matches and the tie.

The 21-year-old also reached the US Open fourth round but, at a career high of 55 in the world, is ranked two places behind Evans, who held match point against eventual champion Stan Wawrinka in the third round in New York before losing in five sets.

Smith said: "I haven't decided yet. I will do that tonight. It is difficult but for the right reasons. Everyone's playing well. Everyone fully deserves to play. Everyone's in good form. It's a good situation."

The Scot at least appears free of injury problems.

Evans has recovered from the foot injury he picked up against Wawrinka while Jamie Murray, fresh from winning his second grand slam title of the year with Brazil's Bruno Soares, is confident a neck problem will have cleared up by Saturday.