JEREZ, Spain -- Both his former team Mercedes and the current Formula One world champion sent messages of support during Tuesday's preseason testing to German great Michael Schumacher as he continues in coma a month after a skiing accident.

Mercedes included a message for Schumacher on the side of its new Formula One car, while four-time defending champion Sebastian Vettel said he was praying for his friend and countryman.

Drivers Lewis Hamilton and Nico Rosberg unveiled Mercedes' silver-and-turquoise W05 before the first session of the preseason began at the Jerez track. The upper part of its chassis just behind the driver's seat carries the Twitter hashtag #KeepFightingMichael.