Mercedes confirmed that Russell had no engines left in his season's allocation of four and would have to take a new one for the Singapore sprint weekend. Team boss Toto Wolff said the Briton would start Sunday's race from the rear of the field.
Russell retired from last weekend's Bahrain Grand Prix in Malaysia with a power unit problem five laps from the finish while running third, leaving him 84 points behind teammate and championship leader Kimi Antonelli.
"The engine wasn't stretched too long. It was the sixth race of the engine and obviously four engines a year, six races per engine when you split it up," Russell told reporters on Thursday.
"We actually put that engine in on Sunday in Budapest, so it was actually the sixth race, but minus qualifying and the practice sessions of Budapest. We were waiting to take the engine penalty... but unfortunately, we've had to take it here.
"But with seven races remaining - that's longer than the engines are designed for, unfortunately - that means I'll be taking another penalty at some point between the next race and the end of the season.
"So it feels a little bit like one thing after another right now, but that's just how the cookie crumbles."
Different car specifications
Mercedes will run different car specifications this weekend, with Antonelli continuing to develop their new package while Russell reverts to the setup that carried him to victory in Baku.
"Actually I instigated the conversation prior to the race on Sunday," Russell added.
"So when the failure happened, it was kind of a no-brainer, because we were kind of 50-50 about it pre-race and I was more in favour of doing it. And that was even pre-race, whereas now it is a total no-brainer.
"So this engine penalty this weekend is just giving a good opportunity to roll back. It's a car that I won in Baku with."
Antonelli remains optimistic about the new package even though the results were not evident in Sepang, where he finished second behind Red Bull's Max Verstappen.
"I think there's an actual improvement. It's just we didn't quite see it in Sepang and I think that's why it was such an outlier," he said.
"But hopefully this weekend we will be able to understand it more, put the car in a better place and be able to use its full potential.
"We really want to understand this new package and try to extract the maximum out of it because the team has done a tremendous job. They've put in so much work on this new package and it would be just a shame to write it off so early."