Capello's joke hid concern that a lack of individual discipline could damage England's hopes of a successful World Cup campaign in South Africa next year.
has often struggled to control his temper with England and was sent off for stamping on Ricardo Carvalho in the 2006 quarter-final defeat against Portugal. He was also substituted by Sven Goran Eriksson after losing his rag in a friendly against Spain in 2004.
Beckham knows from personal experience how the red mist can descend quickly on the pitch following his costly red card for kicking Diego Simeone in the 2002 World Cup defeat to Argentina.
The on-loan AC Milan midfielder is a more mature figure now but he knows it is essential that Rooney retains his fire or he will become a less dynamic player.
Beckham believes it is impossible to completely tame Rooney but he is keen to keep an eye on Rooney so he can avoid the kind of explosions that could lead to more disciplinary problems.
"If you take that side of him out of his game he becomes a different player and a different animal," Beckham said.
"There's no way you want to take that out of him. He knows it's not right.
"It's happened a few times with myself. I probably still haven't been able to control it fully. When things go badly, the team's losing and it's not going well, that frustration comes out.
"As an experienced player you tend to notice those things more when you are a bit older. You see players' reactions and see what can happen next.
"You know what's going to happen. It's all about the passion, which is the biggest thing. You don't want to take that out of him. You can try to get to him in time as a team-mate, but some things are uncontrollable."