Valentino Rossi says he came tantalisingly close to switching to Formula 1 in 2006.

Last month, the MotoGP legend swapped his bike for Lewis Hamilton's Mercedes in a highly publicised event at Valencia.

Rossi, 40, told La Gazzetta dello Sport that he came close to being just a second off Hamilton's pace.

And Luigi Mazzola, the former head of Ferrari's test team, said that when Rossi did several serious tests for Ferrari years ago, Michael Schumacher was impressed.

"In the first test, he spun a dozen times, but over time he did some really amazing laptimes," he said.

"I remember looking at the data in the box with Michael and he had an astonished expression on his face. He was almost incredulous," Mazzola added.

Some 14 years later, Italian Rossi now reveals he came close to quitting two wheels and launching a serious Formula 1 career in 2006.

"I had completed a number of tests for Ferrari and we then sat down with the team management, who had worked out a very comprehensive plan to prepare me for a career in Formula 1," he said.

But Rossi said the deal fell over due to the details.

"The plan said that I had to drive a less fast car to prepare, and I was supposed to be a test driver at first. That's why I decided to decline the offer," Rossi said.