Mercedes is weaker without Niki Lauda at the track.
That is the view of Christian Horner, boss of the German world champions' rival Red Bull.
Lauda, 70, is still recovering from a 2018 lung transplant, and will not be in Australia this weekend.
"Looking in from the outside, Niki's absence is felt," Horner told the Daily Mail.
"Niki would be missed even more if it was a close fight for the title," he added. "He was there partly as a crutch for Toto (Wolff) to lean on.
"So the team will be weaker without Niki having a direct involvement for now," Horner said of Lauda, an F1 legend who is Mercedes' team chairman.
Another man whose absence has been felt in recent times is Bernie Ecclestone, a personal friend of Horner's.
The sport is run these days by Chase Carey, who is grappling with tough and apparently stalled negotiations over the future of F1 beyond 2020.
"Chase has a task similar to Theresa May's with Brexit -- no deal will suit everyone, and the clock is ticking," said Horner.
"Bernie was a dictator and that, in some respects, is what this sport needs."
He thinks it is even possible that 88-year-old Ecclestone will make a return to the sport.
"You never know with him. Maybe one day he will buy the sport back," said Horner. "He is still in good shape. He stays close to the teams, the promoters, governments.
"Liberty have addressed the areas where he was weak -- future technologies and digital media. But in terms of negotiating a deal, there is no better person than Bernard Charles."
