Toto Wolff says he feels sorry for Lewis Hamilton and George Russell having to drive Mercedes' "miserable" Formula 1 cars after an "inexcusable" performance in the Brazilian Grand Prix.
But while they were able to keep up appearances in the opening laps, they soon faced the same tyre degradation woes that hampered them in Saturday's sprint, having to come in earlier than everyone else after a first stint on softs.
Along with degrading pace, the early stop forced them to stretch the next two stints longer than the W14 could cope with as they slid towards the bottom of the top 10.
Hamilton finished eighth after being passed and distanced by Alpine's Pierre Gasly, while Russell retired with 12 laps to go with an overheating engine as he looked set to drop out of the points altogether.
Team principal Wolff appeared shell-shocked by his team's performance at Interlagos with the same W14 car that took podiums in previous weeks.
"Inexcusable performance," Wolff told Sky Sports F1. "There are even no words for that. That car finished second last week and the week before. And whatever we did to it was horrible.
"Lewis survived out there. But, George, I can only feel for the two driving such a miserable thing.
"It shows how difficult the car is, it's on a knife's edge. We've got to develop that better for next year.
"Because it can't be that within seven days, you're finishing on the podium with probably one of the two quickest cars and then finish eighth."
To make matters worse, Hamilton and Russell were easily picked off on the straights after Mercedes opted to go for a bigger rear wing and more downforce.
But that decision, which Mercedes was stuck with after FP1 due to the sprint weekend rules, didn't help its tyre management at all, leaving Mercedes with just another weakness in the race.
"I think straightline speed was one issue, but probably not the main factor," said Wolff.
"The main factor was that we couldn't go around the corners with a bigger wing with the pace we needed and we were killing the tyres, just eating them up within a few laps.
He added: "We are clearly not the world champions on sprint race weekends. We do some good work here on track to get it done.
"But still, that doesn't explain what goes what went wrong. I mean, that car almost drove like on three wheels and not four."
Explaining Russell's retirement, Wolff added: "George's issue was the power unit at the end, we were over all metrics on cooling," Wolff explained.
"It was the last race of the PU, but it is what it is. I'm not sure if we would have finished with the point or not."