Sebastien Vettel says Red Bull Racing will miss Mark Webber's feedback during winter testing following the Australian's injury.
Webber broke a leg after crashing head-on with a car while taking part in a cycling event of the Mark Webber Pure Tasmania Challenge.
The Australian underwent surgery and is expected to miss much of winter testing, although the team are confident he will be fit for the first race of the 2009 season.
Vettel, joining Red Bull from Toro Rosso, says the team will have to be very focused to get their job done while Webber is absent.
"What happened to Mark was a shame and I hope he gets well soon," Vettel told the official Formula One website. "I didn't have the chance to talk to him yet.
"We will proceed as usual with testing and for sure he will be missed but it is more important that he is back next year to get the new car running.
"We have to be even more focused down in Jerez at our next test and can't afford to make any mistakes, as time is valuable."
The German driver had a promising debut as as official Red Bull racer, topping the times for two days in testing at Barcelona last week.
Vettel, who had tested for Red Bull before, admitted he still needs time to get used to the new team.
"From the previous tests I did for Red Bull Racing I know pretty much the whole engineering staff and I'm getting to know them more and more," he added.
"It will surely take some time to get the perfect understanding and finally speak the same language, but we are definitely getting there. And my race engineer will stay with Toro Rosso and I will have new people to work with."