Michael Schumacher has been warned no one will be giving him an inch on his return to Formula One this season.

In days gone by, when Schumacher and Ferrari reigned supreme, the mere sight of the German in his rivals' mirrors often resulted in them swiftly giving way.

But times have changed, and ahead of his comeback that begins this weekend in Bahrain, there is a feeling that while F1 is better for Schumacher being back, the aura of yesteryear has long since faded.

The 41-year-old is no longer 'the red baron', a testament to his time in a scarlet Ferrari, and instead is now driving a Mercedes 'silver arrow' following a 14-year association with the Maranello marque.

And unlike his glory years, when at the most he had one competitor for the crown, this season there are several in with a shout as it is the most open contest for some considerable time.

Aside from his own team-mate in Nico Rosberg, who is unlikely to play the role of patsy as did those at Ferrari, Schumacher will have to contend with a host of drivers desperate for success.

At his old team there is former adversary Fernando Alonso and close friend Felipe Massa, fellow German Sebastian Vettel at Red Bull Racing and Britain's McLaren duo of Lewis Hamilton and Jenson Button.

It is reigning champion Button who has made it clear to Schumacher that no one will roll over for him as they used to.

"He's not going to be slow. He is still going to be the old Michael Schumacher," was Button's assessment of the man who holds virtually every meaningful F1 record.

"He hasn't lost it, his speed won't have changed, and he wasn't going to come back unless he really wanted it.

"But maybe Formula One has changed a little in that back in 2004, 05, 06, you could ask for something and get whatever you wanted.

"Maybe that's not the same now. I'm not sure, we'll see.

"From what I've heard from the team, they think he is quick and consistent, so he'll be a main competitor this year.

"He is with a good team, one that has won the championship, so they know what to do.

"But nobody is going to give him an inch, and it's nice to be in a similar sort of paced car, so we're going to have some pretty good races."

Despite the controversies that have dogged Schumacher throughout his career, Button is expecting his encounters with the 91-time race winner to be within the rules.

"There have been times in the past we had good races together," added Button.

"In 2004, that was very difficult for us because we had a good car, but the Ferrari was a second quicker than anyone all season.

"But there were times during 2005 and 2006 I had some good races with Michael.

"He has always been a good person to race, very fair when I have done so, so I look forward to the challenge again."

Button is certainly relaxed heading into the new campaign, notably spending a few days recently with girlfriend Jessica Michibata, as well as attending the Laureus Sports Awards in Abu Dhabi.

As far as his impending battle with Hamilton is concerned, the 30-year-old is far from distracted, in particular with critics' claiming his younger team-mate will wipe the floor with him.

That merely raises a smile from Button who, after a little over two months, feels immersed in the workings of a team where Hamilton has spent the last 12 years.

"I didn't come to McLaren not confident. I've always had confidence in my ability," insisted Button.

"I've always been pretty good at getting to grips with a new environment, so it hasn't been an issue, and I didn't think it would be.

"One thing I have always worked on is to integrate myself into a team as quickly as possible.

"As for what's going to happen this year. Neither of us know.

"We both know we're extremely quick, and you don't win the world championship unless you're quick, it doesn't matter the situation you are in.

"So it's going to be an exciting year for both of us, and we will see what happens after 19 races."