The England striker will be the centre of attention again on Saturday, seven days after his red card at Fulham which was followed by a wild swing at the corner flag as Manchester United's late-season slump continued.
It once again raised question marks over Rooney's ability to keep his cool in pressurised situations, triggering memories of his dismissal in the World Cup quarter-final with Portugal in Gelsenkirchen as England bowed out of their last major tournament.
Yet David Beckham has already backed the 23-year-old, insisting it would be wrong to try and 'cage' the Merseysider.
And now Capello has followed suit, recalling evidence from his own playing days to emphasise the delicate balance act needed to maintain 'the right level of aggression' is not an easy one.
"I do not need to tell Wayne Rooney to cool down," said the Italian.
"Sometimes, to do that is impossible. I played the game. On occasion I was like that too.
"It depends on the opponents, the result and lots of other things. You need to be aggressive. Just not too aggressive."
Nevertheless, Capello has taken Rooney to one side and had a general chat, reinforcing his importance to the current England set-up, so big it seems Steven Gerrard will be denied the opportunity to fill the same space he has been occupying with such success for Liverpool recently.
"It is very important to have a balance but I am sure it will not be too much with Wayne," said Capello.
"He is a very good, young player. On Saturday he was frustrated because Manchester United were losing and he got a red card.
"But I have never had a problem with him for the national team and I don't expect one, either tomorrow or in the future."
It means Rooney will be set free on Slovakia in Saturday's friendly, a move that will force Gerrard to take up a wider role on the left.
As Gerrard revealed during the week, it will be a roving brief and as Rooney has appeared so often in the same position for United down the years, an element of position switching is guaranteed.
As ever, Capello is perfectly at ease with his work, exuding the air of a man who knows exactly what his aim is, unlike the Steve McClaren era when it seemed players were just being shoehorned into a team in any manner possible regardless of the end product.
Yet Capello also has a very long memory, long enough to remember the quizzical faces that stared back at him in Paris last year as he tried to explain why Gerrard was being used as a second striker.
"I like this," he chortled.
"Against France last year I put Steven Gerrard into the team as a second striker and everyone said 'why?'. Now Steven Gerrard is doing well for Liverpool as a second striker and people ask me 'why am I not playing him there?'
"The last time he played - in Belarus last October - he scored one, nearly got another and played very well. So I don't know why, at this moment, we are speaking about Gerrard's position in the team."
Aaron Lennon has also been promised some involvement, presumably on the right, although whether it will be from the start of a match against the Group Three leaders, arranged as a warm-up to Wednesday's crucial World Cup qualifier against the Ukraine, is dependent on whether Capello hands David Beckham his record 109th cap from the bench.
At 33, Beckham is hardly in the first flush of youth but Capello has kept a close eye on him. And the midfielder's recent performances for AC Milan hint at a man in his prime.
"David is doing very well at the moment," said the England chief.
"He is always in the starting line-up at Milan and has been playing well in training this week."
Both Beckham and Lennon will face extra competition next week as Shaun Wright-Phillips should start training tomorrow after finally shrugging off an ankle injury that has dogged him since Manchester City's victory over Sunderland last Sunday.
Ben Foster might be included against Slovakia as Capello assesses another of David James' rivals for the first-choice goalkeeping slot.
However, with the mood within the England camp good, their coach is confident the outcome will provide further proof of a team moving in the right direction after their defeat to Euro 2008 winners Spain in Seville last month.
"I am very happy because the players have been following me and my way of playing football," he said.
"They have done everything I have asked. That is very important.
"I need to keep that same mentality in the group going forward."