Following yesterday's announcement that Valentino Rossi would be joining Yamaha, Mick Doohan - HRC's general manager of racing - has given a multiple world champion's insight on the biggest shake-up in the premier-class for over a decade.

Mick, who won all his five premier-class world championships with Honda, began by praising his former rider - but also stated that Rossi's motives were as much about business as anything else.

"Good on Valentino if that's what he wants to do," said Doohan, also a former Repsol rider. "He's had a great run with Honda, but at the end of the day business is business. The business side of things has probably been as big an influence as anything on him taking up the option to ride for another team.

"The challenge for any rider in Valentino's position is to stay at the top of the game and making sure the environment is right. He's obviously confident in his ability to pull all the various pieces together to keep winning," added the Aussie, perhaps hinting at the impending departure of Repsol crew chief Jerry Burgess to join Rossi at Yamaha.

During his own record-breaking career, Doohan was rumoured to have made the same decision as Rossi - to voluntarily leave Honda for Yamaha. That never happened and Doohan would ride for HRC until his injury induced retirement in 1999.

Because he never left Honda, the 'thunder from down under' has had to face the 'best rider on the best bike' argument that Rossi himself has begun to grow sick of, but stated that Yamaha have now realised they need a great rider to win again - and have decided to get 'serious'.

Yamaha dominated the premier-class at the end of the 80s and early 90s with the likes of Eddie Lawson and Wayne Rainey. Indeed, their last world crown was claimed by Rainey in 1992 when the American took his third 500cc title in a row - beating the likes of Doohan in the process.

Tragically, Rainey was paralysed while in a tight title battle with Suzuki's Kevin Schwantz for the 1993 world championship. Since Rainey, Yamaha's challenge has been led by the likes of Luca Cadalora, Norick Abe and more latterly Max Biaggi - all riders that Doohan doesn't appear to rate, although his dislike of Biaggi after their 1998 clash has never been in doubt.

"Yamaha hasn't had a really strong rider since Wayne Rainey (pictured leading Doohan in the 1991 Czech Grand Prix) and they haven't won a championship since '92. Valentino knows that, as I did when there was talk I'd go there (Yamaha) at various stages of my career," said Doohan, who took the first of his five consecutive championships in 1994.

"This time around it appears Yamaha are sick of losing. They've decided to do something and get serious about needing to win. They obviously believe Valentino is the rider to go with to get the results they want," he added.

Turning to who will inherit Rossi's status at Honda, the only rider Doohan even named was Nicky Hayden - despite the likes of Colin Edwards, Sete Gibernau and Biaggi being on HRC books - although he thinks the kid from Kentucky is still too 'green' for an immediate championship challenge.

"Honda will still be in a strong position (next season), with plenty of numbers out there," stated Mick. "Nicky Hayden is probably Honda's biggest long-term asset, but he's still a little bit green."

Doohan's concern now appears to be that Honda needs a rider who can take a machine and guide its development to the point where it's a world championship winner - something he credits Rossi with having achieved with the RC211V, while doubting the likes of Biaggi, Roberts, Checa, Barros and Jacque could do it.

"The challenge for the Honda riders will be to match Valentino's consistency race-by-race. Honda also have to keep their development on the correct track," he explained. "You need a rider who can develop the bike. Honda have had Valentino in recent seasons, whereas Yamaha and Suzuki haven't had that."

Looking ahead to next year's much anticipated battle, Doohan - perhaps in an effort to reduce expectation on Honda - still backs Rossi as the man to beat, despite the M1 taking a best GP finish of third this year.

"Valentino is still going to be the guy to beat for next year's championship," commented Mick. "He may need a little time in the beginning to win as dominantly as he did on the Honda, but his consistency will still be a plus."

While Rossi has labelled his new challenge as 'a little bit crazy', Doohan thinks it's a much more realistic proposition - and that the gap between Honda, Ducati and Yamaha isn't as big as many think.

"In all honesty I don't think the Yamaha is that much behind the Honda," Doohan claimed. "While Valentino has been doing most of the winning recently, there's not much between the next Honda and the Yamaha, or the Ducati.

"When I was riding (Luca) Cadalora was on a Yamaha he said you needed a Honda to win," he continued. "When Cadalora got a Honda his results basically didn't change. We've seen the same with (Max) Biaggi when he changed from Honda to Yamaha, and then back to Honda.

"Overall I'm not that surprised about Valentino changing. As I said before, business is business, and Yamaha decided they wanted a winning rider," Doohan concluded.

In the past 10 years, since the start of the 1994 season, Honda have won nine 500cc/MotoGP world championship titles (Doohan: 1994-1998, Alex Criville: 1999, Rossi: 2001-2003) and Suzuki one (Roberts: 2000).

There have been 151 races in those 10 seasons - Honda have won 115, Yamaha 21, Suzuki 13, Cagiva 1, and Ducati 1.