News of Mexican striker Chicharito's imminent arrival at Old Trafford surprised everybody when the Reds announced the pre-contract agreement on Thursday.
The forward, who currently plays his club football for Chivas, is expected to officially become a Manchester United player on 1 July. But Sir Alex told press on Friday morning that it was important to lay the foundations for the deal now... before this summer's World Cup kicks off in South Africa.
"We first received some background knowledge of the boy last October," the manager said. "One of our scouts went to Mexico in December and watched a few games – the reports that came back were very good. At that time we thought we'd just wait because he was only young.
"But then he came into the national team and that created a potential problem: if he went to the World Cup and did well at the tournament then we could be in danger of losing him.
"So I sent our chief scout, Jim Lawlor, over to Mexico for three weeks to watch him and get some more background on the boy. While Jim was there, Chicharito played twice for the national team and also for Chivas: he scored in every game.
"Jim filed a fantastic report on the boy, so last week we sent our club solicitor over there with Jim to do the deal. We're delighted to sign him."
Although bursting with potential, Chicharito is hardly a global household name. But Sir Alex isn't bothered by the 21-year-old's lack of superstar status.
"We like doing these kind of deals," the boss said. "We identify young talent and we’ve been good at that over the years. These are the kind of signings we prefer to make."