Jenson Button was relieved to have survived a bizarre incident during practice at the Monaco Grand Prix that saw a drain cover hit his McLaren.

The 36-year-old suffered damage to the front of his car during FP1 on Thursday after the cover had become loose, with Nico Rosberg sustaining a puncture following a collision with the same object.

Button's day was tricky as his McLaren struggled for grip on the street circuit early on, the incident ending his chances in the first session.

He returned to the track in FP2 after excellent work from his mechanics, but Button was still only able to record the 10th fastest time – nearly two seconds slower than Red Bull's Daniel Ricciardo.

"The day was made tougher for my side of garage by the drain cover, which came loose and broke through my front wing, front suspension, brake duct and floor," he said.

"The mechanics did a great job to get the car ready for FP2, but we've still got a long way to go until we're happy with our competitiveness.

"We were lucky in a way that we just damaged the car. A racetrack is a controlled environment and we take enough risks as racing drivers, but a drain cover lifting in the air for an open-top car is extremely dangerous

"Normally, the safety standards here are very good, but that incident is something we don't want to see again., It was lucky that the drain cover stayed quite low on the ground."