Mark Webber is expecting a far tougher challenge from within his own team following Jaguar's decision to replace Antonio Pizzonia with Briton Justin Wilson.
"I'm sure that Justin will be consistently a lot, lot tougher than Antonio was," said Webber at the German Grand Prix, where he will be partnered by Wilson for the first time.
"I think he's just a stronger person. He's English as well, which will help him here. Let's say that Justin is a lot more complete and should be very quick."
Webber outraced and outpaced Pizzonia for much of this season to score all Jaguar's 12 points so far.
Webber says Wilson will get equal treatment following his switch from Minardi, but the Australian warned his former Formula 3000 rival not to expect any favours on the track.
"Justin will have his side of the garage and I will have mine," said Webber, who was beaten by Wilson to the F3000 title in 2001.
"I think Justin and I can get on, no real egos. Straightforward.
"Everyone is there for his job, aren't they? I'm not going to pump up my
team-mate's tyres. I know he's there for himself. That's how it is.
"We're all big enough to stand on our own feet and get on with it. You've got the same equipment and Antonio and I always had that.
"It's important to be able to beat your team-mate, that's normal.
"It's all fair, it's all very open and I'm sure Justin will be extremely happy with how all the briefings are done. It's all totally open.
"If there's races where he's ahead of me and outqualifying me then of course I won't be overly pleased with it. But both finishing in the points will be absolutely brilliant.
"I don't think it's a great habit for drivers to make excuses and I'm not a big fan of trying to make them.
"He's got his races and it will be business as usual after the first session in Hockenheim."