Jenson Button says critics of Michael Schumacher should understand the demands of becoming competitive again

The Briton also reckons people should not forget what the seven-time champion has achieved during his grand prix career.

Schumacher, 43, returned to the sport at the start of the 2010 season after an absence of three years and struggled to repeat the kind of form that took him to a record 91 grand prix wins.

The German has received some criticism this year after having scored just two points to his team-mate Nico Rosberg's 59, which include one win in China.

The 43-year-old Mercedes driver, however, showed he still has what it takes during last weekend's Monaco Grand Prix, where he was quickest in qualifying. He lost pole position because of a penalty imposed for an incident in the previous race in Spain.

"Michael's come in for a lot of criticism over the last couple of years since he's been back," said Button. "I think we all forget what he achieved in his previous career, if you want to call it that.

"Sometimes it takes time to feel comfortable with a car and comfortable with the people you're working with. But I think he put a great lap together, didn't make any mistakes and he obviously deserved it very much.

"I'm sure when he got out of the car he was very happy, but also disappointed that he was put back to sixth [on the grid] at a place like Monaco."

McLaren team boss Martin Whitmarsh also praised Schumacher's performance in Monaco, but admitted his team will not be "misty-eyed" when it comes to trying to beat him.

"Michael's been a great driver. We like beating him, not him beating us. We're not going to be so misty-eyed. I think you've got to give credit where credit's due. Not always in the spirit that we enjoyed.

"But he did a great job of putting that lap together. Credit to him, but whether he had a penalty or didn't have a penalty, we'd still want to beat him next day."