One very good player moves out and another very good player moves in. Atletico Madrid supporters have stopped fretting about departures because they have good reason to be confident in the people that run the club and their ability to find adequate replacements. In goal Sergio Asenjo became David De Gea, became Thibaut Courtois, who looks to have become Jan Oblak. Playmaker Diego Ribas became Arda Turan. While centre-forward Diego Forlan became Sergio Aguero, became Radamel Falcao, became Diego Costa who has now become that bloodied battering-ram Mario Mandzukic. Atletico Madrid know how to replace stars, from David De Gea (left to right), to Thibaut Courtois, to Jan Oblak . Sergio Aguero (left) was a star at Atletico before being replaced by Radamel Falcao at the Spanish club . Diego Costa (left, squaring up to John Terry) was sold to Chelsea but replaced by Mario Mandzukic (right) Atletico manager Diego Simeone has been pulling the strings at the La Liga club in terms of transfers . The secret of their success is often exactly that – a secret. No club has used the third-party ownership lenience in Spain more to its advantage than Atletico Madrid. Transfers like Radamel Falcao were always shrouded in mystery. How were they able to sell Aguero to Manchester City and hand over a large portion of the fee to the tax man to service their monumental overdraft with the state, and yet still go into the transfer market and get Falcao for an even higher price than Aguero? Jorge Mendes has worked closely with the club and with its managing director Miguel angel Gil Marin across the last five years and there is no question the club have benefited from a healthy relationship with the world’s most prolific agent. It was bordering on comical in 2010 when the Globe Soccer Awards in Dubai picked Gil as its sports director of the year. Mendes played a large part in the setting up of the annual awards – he himself has won agent of the year every year since its inauguration. Atletico playmaker Diego Ribas became Arda Turan at the Vicente Calderon under Simeone . Falcao (right), formerly of Atletico, sits with super-agent Jorge Mendes (left) during a match in France . Atletico's CEO Miguel Angel Gil Marin (far right) give a press conference in Madrid in 2009 . His domination of the best agent award was easier to justify than Gil’s prize that year, coming as it did when Atletico were still hugely indebted to Spain’s Inland Revenue and forced to fire sell every summer. But Gil has led Atletico out of trouble. He has picked his agent friends well, worked the loophole in the system – one Fifa want to close allowing third party ownership in Spain when it is banned in other leagues - and that has played a part in the club's rise. Mendes it was who discovered Costa and brought him to Atletico Madrid via Portugal. The super-agent can also claim to have been the man who saw the huge potential in the unrefined Brazilian front man, overruling scouts that he usually trusted without question and signing the youngster from Lagarto thus beginning the process of making him one of Europe’s top striker. He was loaned him out to four La Liga clubs but was always brought back to Atletico who would eventually win the Spanish Cup, the European Super Cup and the League with him as their centre-forward. Koke is Atletico's brightest homegrown talent and he lined up in midfield on Tuesday night . Mario Suarez and Gabi try to stop Cristiano Ronaldo during the Madrid derby in the Champions League . As well as using the right agents to get the right players Atletico have – like so many teams in Spain benefitted from an extensive and well-run youth system. Koke is their brightest homegrown talent and he lined up in midfield on Tuesday against Real Madrid with Mario Suarez and Gabi who also both came through the ranks at Atletico albeit only arriving at the first team after long spells away from the club. Next season Oliver Torres should return from a hugely successful spell at Porto and line up alongside another off the conveyor build: the hugely impressive Saul Niguez. It also shouldn’t be forgotten that with a very similar squad back in 2012 Atletico Madrid were closer to the relegation places than the European places and even their most blinkered fan would have dismissed out of hand the idea that they would ever be winning the league and playing the Champions League final in the same season any time soon. The reason for the change is perhaps their greatest signing of all – Diego Simeone. He arrived at the start of 2012 just after they had been knocked out of Copa del Rey by a third division side. The likes of former Osasuna winger Juanfran were in the team back then too – he looked a symbol of the oh-so average signings being made by the club at the time. Simeone has been up there with their greatest signings when they made him manager previously . Juanfran was converted by Simeone to full-back and is now in the form of his life at Atletico . Juanfran was converted by Simeone to full-back and is now first choice on the right hand side of Spain’s defence. His transformation is still a symbol, only now it is one of just how much the club and team have progressed. Chinese company Wanda now owns 20 per cent of Atletico Madrid, their tax debt is under control and they are in a position to sign players without having to sell. Having bought so well when they were in a worse financial situation, supporters are optimistic – just as long as they don’t lose Simeone: the real alchemist at Atletico Madrid.
Atletico Madrid 0-0 Real Madrid: Click here for Martin Samuel's report . Atletico have a knack for replacing star players with others just as good . Jan Oblak is the latest, having replaced goalkeeper Thibaut Courtois . Mario Mandzukic looks to be a suitable replacement for Diego Costa .