Beckham has been in sensational form for Madrid in recent months, playing a key role in the club's title charge which could see them crowned Spanish champions for the first time since 2003 when they face Real Mallorca this weekend.
The former England captain is set to join Major League Soccer side Los Angeles Galaxy this summer when his four-year contract with the Spanish giants comes to an end, but there are suggestions from Madrid president Ramon Calderon of a possible U-turn.
There were reports in Spain on Sunday of a potential escape clause in Beckham's Galaxy contract, which Calderon said he would be looking into in a bid to keep the former England captain at the Bernabeu.
Although Galaxy general manager Alexi Lalas has dismissed any suggestion Beckham will not be moving to America this summer, for Capello, any chance of Beckham turning out for Madrid next season is good news.
"Beckham would be a very important player for Madrid, there's no doubt about that. If the club tells me that Beckham is staying, I would be very happy," Capello said in an interview with Spanish newspaper AS.
The Italian coach looked to have brought Beckham's Madrid career to a premature end in January when he announced the former Manchester United man would not play for the club again following his decision to join the Galaxy.
However, Beckham managed to force his way back into the Madrid side and such has been his impressive form in recent months that he also earned a recall into Steve McClaren's England squad.
Capello, who often left Beckham on the bench during the first half of the Primera Liga season, said: "We have all made mistakes regarding Beckham's issue.
"On the sporting side we have made a decision and I am the one that has the maximum responsibility.
"The truth is that with him (Beckham) we made a mistake.
"Beckham is a great player. Now he is playing at the same level as he did at Manchester (United).
"He is a player that has recovered his physical and psychological condition because he was upset not to be playing with his national team.
"For every player, the national team is important and for English players more so."
Beckham has yet to win a major trophy during his time at Madrid, but that could be rectified this weekend when the final round of Primera Liga fixtures take place.
Last Saturday's 2-2 draw at Real Zaragoza kept Madrid just ahead of Barcelona at the top of the table and if Capello's team beat Mallorca at the Bernabeu on Sunday then they would be crowned champions.
Both Madrid and Barca, who play already-relegated Gimnastic Tarragona in their final match, are currently locked on 73 points but Madrid are on top due to their better head-to-head record against the Catalan side this season.
Beckham looked to have suffered a recurrence of the left ankle injury he picked up on England duty late on in the match against Zaragoza, although he did finish the game.
Madrid will monitor the situation in the lead-up to Sunday's encounter, but Capello said after the Zaragoza match that he was confident Beckham would be okay to face Mallorca.