BARCELONA, Spain - Mercedes team principal Ross Brawn is ill and will miss the 2012 Spanish GP.Technical director Bob Bell will take charge, with team chief executive Nick Fry and Mercedes motorsport vice-president Norbert Haug also at the Circuit de Catalunya.A Mercedes spokesperson said Brawn, whose team won the Chinese GP, was expected to be back for Monaco later in May.The team gave no details about Brawn's illness.'CHALLENGE FOR US'Michael Schumacher said: "Naturally we will miss him, be sure about this, but he will be in contact with us and support us in his maximum way. We had to deal with his absence during some of the Ferrari days and will have to deal with it here this weekend. "With all his experience and knowledge it is going to be certainly a challenge for us."Brawn missed a few races while at Ferrari due to back problems and then took a year out of the sport altogether when Schumacher left Ferrari at the end of 2006 and began a retirement that lasted three years.The team boss won multiple World championships for Benetton and Ferrari as a technical director and then led his Brawn GP to the 2009 title after previous owner Honda pulled out. Then Mercedes took it over.The Spanish GP is Round 5 of the season and first this year in Europe.Stay with Wheels24 for the 2012 Spanish Formula 1 weekend.