Jun.20 (GMM) Red Bull Racing is likely to settle its 2009 formula one driver lineup "in the summer", team boss Christian Horner has said.



The Briton did not, however, want to respond to rising speculation that David Coulthard will be replaced at the end of the season by Sebastian Vettel.



"I would not like to say much about it at the moment," Horner explained to the newspaper Kleinen Zeitung.



"The decision however could be made in the summer," he added.