Eight-time grand slam champion Andre Agassi believes American men 's tennis has to 'regroup at grass roots level ' if it ever wants to boast a world number one again . The United States take on Great Britain in the Davis Cup in Glasgow this weekend , hoping to avenge last year 's 3-1 defeat in San Diego . World number five Andy Murray will lead the charge for Britain and goes into the first-round World Group tie as the stand-out singles player , with America 's John Isner and Donald Young ranked only 20th and 47th respectively . USA legend Andre Agassi ( pictured in 2009 ) says America must 'regroup ' its grass roots tennis set-up . World number five Andy Murray will lead the line for Great Britain at the Davis Cup this coming weekend . USA 's Donald Young stretches to return a shot to Ivo Karlovic during the Delray Beach Open on February 22 . John Isner of the United States plays a backhand during his third-round match at the Australian Open 2015 . It is a far cry from the days of Agassi , who lifted the Davis Cup in 1990 , 1992 and 1995 alongside the likes of seven-time Wimbledon champion Pete Sampras and four-time major winner Jim Courier . The last time America produced a male grand slam winner was 2003 , when Agassi won the Australian Open and Andy Roddick triumphed in Flushing Meadows . 'Being the next Andy Roddick or the next Andre Agassi will still leave you shy of winning tournaments these days . That 's the truth , ' Agassi told Press Association Sport . 'Will we ever have a number one player again ? That 's achievable , of course it is , but the four guys at the top now - Roger Federer , Rafael Nadal , Novak Djokovic and Andy Murray - they have redefined what this sport is all about over the last 10 years . 'You need something unique these days to make inroads , especially growing up in a country that does n't have red clay courts . American tennis great Pete Sampras won the Wimbledon championship seven times during his career . Agassi has singled out Switzerland 's Roger Federer as one of the 'four guys at the top now ' He has also placed Serbia 's Novak Djokovic on that list , pictured here at the Dubaio Duty Free Championships . Spain 's Rafael Nadal returns a ball against Argentine Juan Monaco during the final of the ATP Buenos Aires . ' I do n't know where Andy spent his childhood playing ( he spent time in Spain as a teenager ) but he plays the game like he was n't just playing indoors . 'We do n't have that in America . We have a lot of fast court players and the ones who do shine are the ones who bring a different equation . 'Isner , for example , is a monster , he 's 6ft 10 plus with a huge game , so we have to regroup at a grass roots level . ' Despite a shock defeat to 18-year-old Borna Coric in Dubai last week , Murray will be expected to win both his singles matches in Glasgow . That means the tie could depend on the doubles rubber , where Andy and Jamie Murray are set to face American twins Bob and Mike Bryan , the most successful duo of all time . American duo Bob ( left ) and Mike Bryan are set to come up against Great Britain 's Jamie and Andy Murray . 'It 's a tough ask for both teams because there 's very little that separates it , ' Agassi said . 'We have a big advantage in our doubles but you guys have a huge advantage with Murray . 'People think he 's coming off a bad loss but I 've got news for you ; he 's going to be ready to go in a week and he 's going to be playing his best tennis in front of a home crowd . ' I hope we can get over the finishing line and I 'll have my fingers crossed like the rest of us . ' Agassi has previously admitted an interest in a coaching career and is even considered a potential mentor for Murray , who idolised the American as a junior . ' I enjoy the idea of coaching but I would n't physically , emotionally and mentally be able to do the job that I would want to do , ' Agassi said . 'You ca n't just step in and give advice . Coaching is n't talking , it 's learning . 'The things I say about Andy are not going to be a surprise to him . 'It 's finding out what that switch is , it 's getting them to see something a different way and you ca n't do that until you spend time and learn with them . ' I ca n't commit the time now , even if I wanted to , I have too many responsibilities . 'That does n't mean there would n't be a time in the future , but I ca n't do it at the moment . ' Agassi is tipping Murray to recover from his shock loss to Borna Coric and perform well at the Davis Cup .
USA tennis legend Andre Murray says the country needs to 'regroup ' He feels they are a long way off producing another world number one . Murray has backed Great Britain 's Andy Agassi to impress at the Davis Cup . Agassi enters the tournament off the back of a shock loss to Borna Coric .