"Diego Costa. Two years ago," came his straight reply. Carlos Queiroz knows that Cristiano Ronaldo and Lionel Messi are unobtainable, so he's gone for the best in the class below, a striker sandwiched between the world's best two players in Spain's top scorers' chart this season.
Sir Alex Ferguson long anointed Queiroz as his successor, but when his time came to step down the Portuguese had left the club. He's not United's manager. David Moyes is and he's watched Costa several times this season and is also a big admirer. Who wouldn't be?
The Brazilian, who has chosen to represent Spain at international level, is second top scorer in the league so far with 21 goals, three behind Ronaldo and five ahead of Alexis Sanchez in third. Despite an injury hit season, Lionel Messi is fourth with 15.
Costa, 25, has the highest conversion rate of shots to goals in La Liga with 38.8% of his shots going in. He also has the best shot accuracy: 71% of his strikes are on target, ahead of both Messi (70%) and Ronaldo (59%).
In Europe, Costa has been equally lethal, scoring three of Atletico's goals in their 5-1 aggregate victory over AC Milan which meant there will be no Italian team in the last eight of the Champions League for the first time in five years.
All of which makes you wonder why Brazil didn't fight harder to keep a player who only played for Spain for the first time this month, when Vicente del Bosque called him up to play against Italy. Costa had been granted Spanish nationality after five years residency. Brazil hadn't called him up until 2013 for two friendly games.
They were not impressed when Costa said he wanted to play for Spain, though he feels that the Brazilian federation are trying to turn his country against him so that he'll get a hostile reception in the World Cup finals. He's right.
Costa has sprung to international attention since he replaced the outgoing Radamel Falcao as Atletico's principal front man, switching positions from out wide. Atletico feared their team would be badly depleted without the Colombian, but Costa has filled in better than anyone expected, spearheading their epic season which sees them second in the league ahead of Barcelona and into the last eight of the Champions League.
Atletico appeared to blow up two weeks ago when they lost 3-0 at Osasuna. That made it two defeats in three games, but they held Real Madrid a week later and beat Celta Vigo away at the weekend.
Costa scored three against Milan, the only goal in Italy followed by two in the Calderon - the first a volley at full stretch which came from a cross from Koke. The pair have superb synergy. More than half of Costa's goals have been assisted by Koke, with the later stating how they talk after training about how they link up.
He'd not scored a Champions League goal before two goals against Austria Vienna in September. This is only Costa's second term as an regular starter with Atleti. He's worked hard to get his rewards, for nobody can say he's had it easy.
"It's been difficult, with loans, operations and rehabilitation," Costa said of his career to date, "but life is a constant lesson. Sometimes you don't have the same touch of inspiration as other days, but if I give it everything I'll reap the rewards."
A street footballer until 16, Costa was spotted playing in Brazil and moved to Portugal with Braga at 18, where he played in the club's reserves. He was loaned out to second division Penafiel, then sold to Atletico Madrid in 2007 - though until then he stayed with Braga where he made his first team debut.
"I'm surprised at how well he's done," says Forlan. "He's been called a world class player and I didn't see that at Atletico. If he keeps going as he is then it will be right to call him world class."
Atletico hoped he could replace the outgoing Forlan in 2011, but Costa suffered a serious knee injury in pre-season training. Another setback. When he recovered, he was loaned him to Rayo Vallecano in 2012, where he excelled.
If there are slight criticisms then they're twofold. One, this is a breakthrough season as a world star and he wouldn't be the first player to have one great season. World class players have four great seasons in five. Two, his physique.
It's of course to his advantage that he's big, built like an old fashioned English centre-forward strong enough to trouble any defender. Costa's upper-body strength is a key factor in his ability to overcome opponents. He's also more than a bully who barges past players. But he's a player, like Wayne Rooney, who needs to be fit, needs to be playing every week to stay on top of his physical form.
Coach Diego Simeone has been crucial to his development. "He’s been important not only for me, but for the whole group," says Costa, who has calmed his previously suspect temperament on the pitch. "He’s changed our way of thinking. He asks us to get into every single game as it were the last one of our careers, demanding you to leave all you can on the pitch, always showing that there’s room for improvement.
"It wasn’t like this before his arrival. Another name that should be considered on this is our fitness coach Oscar Ortega, one of the strengths of our side. He doesn’t let anything go unnoticed, is always around the players. Football needs to have this work with more emphasis on the physical."
With the finales of the Champions League, the Primera Liga and the World Cup finals still to come, Costa's magnificent season could still be yet to reach its peak.
Andy Mitten - @AndyMitten
- Sports & Recreation
- Diego Costa
- Lionel Messi
- Cristiano Ronaldo
- Diego Forlan
- Manchester United