The 22-year-old told the Swiss team he was not fit enough to race on the Sunday after struggling through Friday’s practice session at the Albert Park circuit.
Wehrlein injured his back in January and took time off to recover, missing the first day of winter testing in Barcelona. He was concerned his lack of race fitness would prevent him from reaching his peak in Melbourne.
“My back is fine but I took a step back in terms of fitness and I’m trying to catch up,” Wehrlein said. “I am not feeling like I could do a whole race at my best level.
“Nine weeks ago my injury happened. Then I couldn’t train as hard as I wanted and as I needed to do. I feel like I couldn’t do the whole race distance. If I think after a few laps, ‘That’s painful,’ I’m losing concentration, I’m losing focus and this would be too high risk.”
Some felt Wehrlein should have toughed it out and jumped behind the wheel. Aussie F1 great Mark Webber certainly lost respect for the youngster.
“I am not a fan of Wehrlein,” he said. “That’s backed up by his soft call saying he wasn’t fit enough. I’m not too disappointed about that change.”
But Sauber team principal Monisha Kaltenborn said nobody had any right to blame Wehrlein for making the decision he did.
“He just needs time,” Kaltenborn told Motorsport.com. “I think it is really awful how people think they have any sort of competence to say anything about him.
“They just have their weird views from wherever they come and have no authority at all to judge over anyone. I think it is rather appalling how people think they can judge this and they should look at themselves first.
Wehrlein hasn’t had the chance to don the Sauber colours on race day.
“It takes a lot for someone so ambitious to openly admit and say, ‘Guys, in these circumstances, I cannot cover the entire race distance.’
“So one should rather appreciate that kind of openness and honesty, which is not easy to maintain with the kind of pressure these guys have.”
Formerly with Manor, Wehrlein — part of Mercedes’ junior driver program — was overlooked by the Silver Arrows when it came to replacing the retired Nico Rosberg. Valtteri Bottas took the seat and the German decided to head elsewhere in search of more opportunities.
Kaltenborn said the team had no idea Wehrlein was struggling so much in the lead up to the year’s first race.
“Not at all. I would never have done this otherwise,” she said. “You cannot have an indication for this because then you know something really isn’t right. We started building him up because that was the right thing to do.
“We came here with the clear intention that he is going to drive all weekend.”
In Wehrlein’s absence, Antonio Giovinazzi and Marcus Ericsson drove for Sauber. Ericsson suffered a collision on the first lap resulting in a hydraulic failure which ended his race and Giovinazzi finished 12th.