Button says Monaco return poses no pressure

"If I get to Turn Two and I feel totally out of my depth, I will drive off into the sunset and not come back," the 37-year-old Briton told reporters on Monday, smiling as he said it.

"So it is fine. It is not a problem. I have no pressure."

The 2009 world champion and former Monaco winner left Formula One at the end of last season, handing over his seat to Belgian rookie Stoffel Vandoorne, and has moved to California where he has focused on triathlon.

He is returning for the showcase race as a replacement for Spaniard Fernando Alonso.

The Spaniard is missing the race around the streets of the Mediterranean principality in order to compete in the Indianapolis 500 on the same day, with the double champion qualifying fifth on Sunday.

McLaren are the only team yet to score a point this season, their Honda-engined car beset by engine problems and lack of performance.

But Button did not have to worry about that as he immersed himself in the McLaren simulator at the team's Woking headquarters.

He said negotiating Monaco's tight and twisty street circuit in the virtual world, which replicates every bump and curve and can be adjusted for different conditions, still had its difficulties, however.

"I also fell in the port twice today, and hopefully that's not going to happen," he said.

"After Turn One, you go up the hill and I fell off on the right hand side. And rolled. I've never rolled in the simulator before - but I rolled. Lucky enough, the impact isn't as big as in reality but you still get a jolt and a bit of G-force."

Despite McLaren's problems, Alonso managed to qualify seventh at the previous race in Barcelona and Button saw that as a positive sign that the car could be competitive in Monaco with new updates coming.

"What a step forward," Button said. "He obviously did a great lap but it shows how much improvement the team has made. It is massive.

"If Alonso can put it seventh in Barcelona then we should be looking sweet for Monaco," he said, adding one caveat: "First of all I've got to see if I still know what to do when I get in the car on Thursday."