The England manager was at Old Trafford as his star striker broke a five-month goalless spell by converting a penalty for Manchester United against West Ham last weekend.
Centre of attention: Rooney trains with England at Wembley
VIDEO: Capello on England's clash.And after watching the 24-year-old in training this week, Capello said: 'He's good, he's back and I'm happy because he scored a goal.
'I monitored him during the last game that he played against West Ham.
That's my boy: Capello watches over Rooney
'Rooney runs a lot around the pitch, he's free to move where he decides to go. Rooney will play tomorrow in style.'
Rooney played with anything but style at the World Cup, when he was hampered by an ankle injury and failed to score in four matches despite being trumpeted as one of the world's greatest players.
Capello is closing on finalising the rest of his starting XI, with Everton defender Phil Jagielka set to start despite suffering with an ankle injury in recent days.
'The keeper, (Joe) Hart, Rooney, Steve (Gerrard), (Gareth) Barry, (Ashley) Cole, (Glen) Johnson, Jagielka, more or less. I know 10 or 11, with a little doubt about one,' said the Italian.
'The training was really good, the players are OK and some problems we had in the last two days are getting better.
'(Jagielka) is fit, he trained well, there is a little bit of pain but I think for tomorrow he will be 100 per cent.
Scoring touch: Rooney scores from the spot against West Ham
'I'm not concerned but I know that the central defenders will play for the first time together tomorrow. I hope they will be really focusing every moment of the game and I hope Cole and Johnson will help these two players, and also the midfield.'
Ready to go: defender Jagielka
Capello dismissed concerns the pressure of a disappointing World Cup had got to him, and backed his players to regain the form which saw them qualify for the tournament with nine wins from 10 games.
'It's part of a manager's job,' Capello said. 'When you win, you're the best. When you lose, you're the worst.'
And the Italian admitted he had changed his approach since South Africa.
'I learn something after a new experience,' he said. 'I changed something, but not a lot. We have to play without fear, I thought the players trained very well, with confidence, and I hope tomorrow we can see the same during the game.
'Bulgaria will not be an easy game to play, they are really good technically, they defend with nine players- one forward - and they play on the counter, really fast.
'Theirquality is good but we have to win, we have to play well, and I hope also the fans will support us during the game.'
Asked about his plans for former England captain David Beckham, who missed the World Cup, Capello said: 'The door is open for all the players, always.
'I prefer at this moment to choose young players.'
Capello thwarted as Everton's Arteta will never be called up by EnglandQuestion time for Fabio Capello! England manager needs to find answers fastWe're right behind you, Fabio! Barry backs under fire England boss CapelloMARTIN SAMUEL: Show respect - Fabio Capello is no clown