McLaren doubted Montoya's commitment

Confirmation that Pedro de la Rosa would take Montoya's place in the McLaren line-up came just two days after the NASCAR announcement.

"His decision to go to NASCAR brought into question the level of commitment and dedication that he would be able to bring to the balance of the season," Dennis told BBC Radio Five Live.

"Clearly all the time that Juan Pablo was driving for McLaren he was a) seeking to positively influence the management in respect of him staying with McLaren, and b) positively influence the other team principals who represented his options for Formula One.

"If that objective is clearly removed from his own mindset, it was my judgement that his commitment - which is not just driving hard, it goes beyond that - was brought into question."

Dennis believes that Montoya has acted rashly in the past week.

"Some thinking time was the most appropriate reaction to a decision that clearly didn't have that value attached to it," he said.

"This was clearly a spontaneous, reactive decision, taken and executed within a very small window of time. It did not involve his management and it certainly did not involve our team.

"My experience in life is that impetuous actions are just that, and that people very often reflect on what they've decided to do and subsequently regret it."

Despite this criticism, Dennis maintained that Montoya could yet be recalled to the race squad later in the season.

"I think a period of reflection was the right approach," said Dennis. "I don't want to have, and nor does anyone else in the time, a closed mind to pursuing Juan Pablo's involvement in the balance of the season if we're convinced that it can be attacked with the right level of competitiveness and commitment."