BERLIN, Madrid - With Michael Schumacher set to return to Formula One next weekend, Mercedes GP team boss Norbert Haug on Sunday played down the expectation on his team ahead of the opening Grand Prix in Bahrain.

Seven-times world champion Schumacher will break his three-year hiatus from the sport at the eagerly-anticipated Bahrain race on March 14 when he turns out for the German outfit.

The 41-year-old signed a three-year deal which will reunite him with team principal Ross Brawn, who masterminded all of his previous world drivers' championships titles at both Benetton and Ferrari.

But Mercedes team boss Haug does not regard his outfit as amongst the favourites with McLaren's Jenson Button set to begin the defence of his world crown in Bahrain alongside team-mate Lewis Hamilton.

"I do not see us as the favourites for the first race, but we are on the right path to be able to challenge at the top," Haug told the Frankfurter Allgemeinen Zeitung on Sunday.

"But we haven't won a single point yet and we want to make sure we can stand up for ourselves and give the answers on the track.

"In my opinion, we will not challenge for the podium in the first few races, but we will definitely show up afterwards."

With Schumacher coming out of retirement, media interest is intense in Germany where the former Ferrari driver is one of the nation's favourite sons.

"When the seven-times world champion surpisingly decides to return, it is quite obvious where the media interest lies," said Haug.

"That could all change very quickly if Nico Rosberg wins a race or challenges for a podium place, we should not forget that."

And Haug was quick to talk up the prospects of 24-year-old Rosberg, who finished seventh in the 2009 world drivers' championship.

"I have never seen Nico (as being in Schumacher's shadow)," said Haug.

"I cannot say which of the drivers will have their noses in front."

Germany compatriot Sebastian Vettel has said he intended to upstage compatriot Michael Schumacher by winning this year's Formula One title.

Vettel, the 22-year-old Red Bull driver, was second in the table last season behind world champion Jenson Button of Brawn GP.

"After last season, I have only one objective: to become world champion," Vettel told the Berliner Zeitung.

"For the younger drivers, it is a challenge (to have Schumacher racing again), because we never thought we would have a chance to test ourselves against him again.

"From a statistical point of view, he is the best."

Vettel made his Formula One debut in 2007 and became the youngest-ever winner of a Grand Prix when he took the 2008 Italian title.

But Hamilton does not even see Schumacher as a threat.

Instead Ferrari's Spanish star Fernando Alonso is his biggest threat, the British driver told the Marca daily on Saturday.

"He's a fantastic driver with a very good car, yes potentially, he's my most difficult rival (for the title)," Hamilton was quoted as saying.

The 25-year-old Englishman had a bitter rivalry with the two-time world champion when the pair were teammates together at McLaren in 2007.

Hamilton, the 2008 champion, also said that Michael Schumacher "could not be forgotten" as he makes his F1 comeback for the new Mercedes team with an eighth title in his sights.

He described the 41-year-old German as a "legend of the sport" but said he was not currently the best driver on the grid.

Hamilton is hoping to reclaim the title this year after losing it to fellow Briton and now his team-mate Jenson Button in 2009.