Jenson Button did not need to be persuaded to return to F1 for next month’s Monaco GP and will be back up to speed within “10 laps” of practice, according to McLaren chief Eric Boullier.

Just six months after beginning a sabbatical which is expected to give way to a full F1 retirement, Button will be back in a McLaren for F1’s blue-riband race after Fernando Alonso chose to compete in the similarly prestigious Indianapolis 500 on the same weekend.

With Alonso’s Indy drive only coming together in the last seven days, Boullier says his initial discussion with Button lasted all of “two minutes” before an agreement was reached on the 37-year-old’s return.

“I rang him and we discussed it and his first reaction was just ‘great, I’m so excited’,” the McLaren racing director said.

“It was an easy discussion, to be honest – very straightforward. He was the choice. He had a contract with us anyway, but you could feel his excitement over the phone was real and I’m happy that it will be part of his adventure.”

 Although Boullier confirmed Button has completed some simulator work at McLaren’s Woking HQ since stepping down from a race seat last November, the Briton has not driven the new MCL32 on a race track.

And his first such real-life experience will come in Thursday practice at Monaco after Button and the team decided he would not run in next week’s two-day Bahrain test.

“We discussed this at length together,” explained Boullier. “Jenson obviously spent 17 years racing in Formula 1 and he actually drove the kind of levels of downforce we have today.

“Going through the difference on the technicalities to drive this car, we agreed that the track layout here [in Bahrain] or even practice running in Barcelona [at the Spanish GP] would not be very useful.

“He’s fit, he’s ready and having Oliver Turvey in the car next week is part of fine tuning the correlation with our simulator. Our simulator in MTC [McLaren Technology Centre] is very accurate now and we both believe that it’s better for him to spend a couple of days in the simulator driving this car into the streets of Monaco.”

And, although Button will have been out of an F1 car for half a year by the time of the Monaco GP week of May 25-28, Boullier has no doubt the 2009 world champion will be at his best very quickly.

“He is very talented, a world champion, and has had a long experience in Formula 1,” he added.

“I can guarantee you that by lap 10 in Practice One he will be ok.”