The Manchester United striker was considered a major doubt a fortnight ago because of his ankle problem and missed the Red Devils goalless draw with Sunderland.
Rooney was also facing allegations regarding his personal life and had looked a shadow of his former self when playing for United.
Back in the game: Wayne Rooney is raring to go against Montenegro
But he had shone for England in their two Euro 2012 qualifiers against Bulgaria and Switzerland, and his availability is even more important as Darren Bent is sidelined with a groin injury.
England manager Capello said: 'Rooney will play. He is feeling good. I spoke with Wayne and he told me his ankle is okay.
'He trained fantastically and without pain. He is in a good moment. I spoke with him about different things and he is happy.
Ready to roar? Rooney is desperate to put his recent personal woes behind him against Montenegro
'Rooney will play tomorrow in the same style as he played against Switzerland.'
That will mean Peter Crouch earning a recall, playing just ahead of Rooney.
Rooney had a hand in the build-up to all four goals against Bulgaria at Wembley and found the net against Switzerland in Basle.
Rio Ferdinand, restored as captain after recovering from injury, is convinced Rooney will be at his best against Montenegro.
He said: 'Wayne has been under immense pressure because of the (personal) reasons we know.
'He has been fantastic in training. He has been the same old 'Wazza' around the training ground, which we all love. If we are going to win anything, we need him playing to his tip-top form.
'I am sure we will see a good performance from him tomorrow.'
Bent had been earmarked to start against Montenegro after scoring his first senior international goal in Switzerland.
He has started the season in fine form for Sunderland after the disappointment of not making the World Cup squad.
But he felt pain in his groin during today's training session at Wembley and his bad luck will offer another opportunity for Crouch.
Partner: England's Peter Crouch (right) is likely to start alongside Rooney
Capello confirmed: 'Bent is not fit. He will not play. He felt some little pain (in the groin).
'It is hard on him after scoring the goal against Switzerland but this is the situation and I will play Crouch.'
Crouch has averaged a goal every other game throughout his England career and has hit the target 20 times for his country.
But he has struggled to win over Capello in terms of being a first-choice selection.
Capello and Ferdinand are both aware of the threat that could be posed by Roma striker Mirko Vucinic tomorrow.
He scored the winner against Switzerland on Friday and celebrated in bizarre fashion by taking off his shorts and placing them on his head.
Still skipper: Rio Ferdinand will lead England out against Montenegro
Capello said: 'It was a strange celebration, very strange. He was really happy. It was a very important goal. He is one of their dangerous players.
'Montenegro are a good team, defend well and are very dangerous on the counter-attack and also the quality of some players is very high.'
Ferdinand said: 'I have played against Vucinic a number of times for Manchester United in the Champions League. I said then I thought he was a very talented player.
'I have seen him before. We know who he is. But they have a number of good players. We will be doing all the analysing to make sure there are no surprises.
'His celebration is not one you would get away with in the Premier League, although I am sure there were a few ladies out there who enjoyed it!'
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Explore more:People: Darren Bent, Peter Crouch, Fabio Capello, Wayne Rooney, Rio Ferdinand Places: Montenegro, Bulgaria, United Kingdom, Switzerland