An energy-sapping summer of tennis isnt quite over for Andy Murray.His last task is potentially playing three matches -- two singles and a doubles -- for Britain in a Davis Cup semifinal against Argentina, starting on Friday, to keep his country on course for a second straight title.Ill try and fight as hard as I can this weekend and help the team as much as possible, Murray said on Thursday, and then Ive got a break after that, which I need.Since May, Murray has won Wimbledon, the Olympic tournament, the Italian Open, and Queens, as well as losing in three finals, including at the French Open.The Davis Cup is a big deal to Murray, though, and he is back for the semifinals after missing the last-eight win over Serbia straight after Wimbledon.Murray will open the semifinal in Glasgow with a singles against Juan Martin del Potro, in a replay of the Olympic final won by Murray in four sets last month. Kyle Edmund takes on Guido Pella in the second singles.On Saturday, Murray will partner his brother, Jamie, in the doubles against Federico Delbonis and Leonardo Mayer.In reverse singles on Sunday, Andy Murray plays Pella, and Del Potro takes on Edmund.Hes a very robust guy, both physically and mentally, Britain captain Leon Smith said of Murrays potential workload, so dont be surprised to see him do it.Murray will miss his grandfathers funeral on Friday to play in the Davis Cup.Britain is attempting to retain the Davis Cup for the first time since 1936, having won the tournament for the first time in 79 years in November.This is going to be a very, very tough weekend for us to win this one but all the players want to get through it and its a big goal for all of us, Murray said. Trying to reach another Davis Cup final would be a fantastic achievement.There have been so many big events in the last few months and its been difficult to sort of prioritize every single one, but at the end of a long summer, if we get through this one, you know, weve got an opportunity to win again so well give it everything this weekend.Murray and Del Potro are the countries top players, so would usually expect to play each other on Sunday. However, Del Potro is ranked a lowly No. 64 as he works his way back from a long absence during which he underwent three operations on his wrist.His comeback is good for the world of tennis, Argentina captain Daniel Orsanic said, so you can imagine what it means for us Argentinians.Its Croatia vs. France in the other semifinal. Adidas Stan Smith Wholesale . Hargreaves began his career in 2008 with the Winnipeg Blue Bombers and has played with the Edmonton Eskimos and last season with the Saskatchewan Roughriders. Cheap Adidas Stan Smith Shoes . Canada is now down to its 22-player limit, although but players wont be registered until Christmas Day. Changes could still be made as a result of a suspension or injury. http://www.cheapstansmith.net/ . The native of Mont-Tremblant, Que., captured a World Cup downhill event Saturday, his second this year and fifth career victory on the circuit. Adidas Stan Smith Authentic .ca looks back at the stories and moments that made the year memorable. Adidas Stan Smith Clearance .com) - The Chicago Blackhawks aim for their third three-game winning streak of the season when they host the struggling Edmonton Oilers in Sundays battle at the United Center.Andy Murray will be required to conjure up more of his remarkable powers of recovery if he is to make it through to the semi-finals of the ATP World Tour Finals on Friday. Having beaten Marin Cilic and Kei Nishikori, the world No 1 only needs to win a set against Stan Wawrinka to guarantee his passage through to the semi-finals at the O2 Arena for the first time since 2012. Six months half price Upgrade to Sky Sports to watch Man Utd v Arsenal on Saturday and get the first six months half price But he will have to drag his weary body through another tough test as an explosive season finale draws ever closer. World No 3 Wawrinka showed much better form in beating Cilic on Wednesday than he had in his limp loss to Nishikori and the Swiss knows that a straight-sets win over Murray would maintain his record of always reaching the last four. Sky Live: Murray v Wawrinka Andy Murray takes on Stan Wawrinka at ATP World Tour Finals Nothing comes easy against the very best players in the world, let alone against the US Open champion who has suddenly clicked in London - something Sky Sports analyst Mark Petchey acknowledges.Wawrinka is always the wildcard in the pack, hes the guy that when hes confident, hes got the power to get through tough surfaces and he does a lot of things well, said Petchey. He moves better than people give him credit for and as I say it was an intelligent performance with the use of the slice. Its not just about the power and the showbiz tennis. Wawrinka beat Murray at the Tour Finals in London last year Friday will be the 17th meeting between the pair, with Murray leading the head-to-head record 9-7, and when they do clash, sparks usually fly.Wawrinka, who sealed his first major title at the 2014 Australian Open before winning an ATP Tour 500 and 1000 event, last faced the Scot in the French Open semi-finals.That was one of Murrays most impressive performances of the season and ended a run of three straight losses to Wawrinka, including at the O2 last year with qualification at stake. Murray also suffered a 6-1 6-2 defeat to Wawrinka at the Monte Carlo Masters in 2013 Wawrinka, who faces a battle to hold on to the world No 3 ranking, said: All I know is, if I want to have a chance to qualify, I need to win.dddddddddddd Thats all Im trying to do.Im going to try to play my best tennis, to beat the world No 1. Its going to be a tough match. We played each other many times. The hardcourt surface at the O2 Arena will suit Wawrinkas heavy hitting style of game from both flanks, but hell have a job breaking down a resilient Murray. The 29-year-old is a totally different prospect to the one he faced in the US Open quarter-finals and Monte Carlo Masters in 2013.Arguably the most famous meeting between the two came under the Wimbledon lights in 2009 in a contest lasting three minutes short of four hours, which the Scot won in dramatic fashion. Could it more of the same on Friday? Mark Petchey and Greg Rusedski discuss Murray’s epic win over Nishikori and his chances against Wawrinka Obviously its going to be a tough match, said Petchey. Theyve had a lot of tough matches in the past and this will be another one.Andy is the form player right now and Im sure inside hes feeling pretty invincible every match he steps out on court. WATCH: Murrays double take Andy Murrays remarkable winner against Kei Nishikori was reminiscent of his winner in Rome Weve got a couple of guys out here who are Grand Slam champions who both believe they can win every single match they step out on court with, no matter who theyre playing, where theyre playing in the world, on what surface theyre playing in the world.So both of those players are going to go into that clash on Friday believing and knowing at the moment they still need to win it. Murrays service syndrome over? Andy Murrays service syndrome may be a thing of the past Should Murray win his group, he would play Milos Raonic in the semi-finals on Saturday in a repeat of their Wimbledon final and Australian Open semi-final. Let battle commence...Check our game-by-game coverage from all group matches at the ATP World Tour Finals in London - including Andy Murray v Stan Wawrinka on Friday afternoon - on skysports.com/tennis, our app for mobile devices and iPad and our Twitter account @skysportstennis. Upgrade to Sky Sports now to watch Man Utd v Arsenal this Saturday and get the first six months half price! Also See: Murray beats Nishikori in epic WATCH: Murrays double take One of the best matches ever Wawrinka keeps hopes alive ' ' '