Both Stella and Mercedes F1 Boss Toto Wolf said it was not yet clear whether the oil leakage was caused by chassis or engine problem.
Stela also praised the piastry, in which he made pole and victory after a steps behind Noris in practice sessions.
“I would say that the Oscar weekend has been a specific weekend for the Oscar because we have seen the characteristic of construction through weekends in practice, cachet in learning,” Stela said.
“We have seen delivery at that time which matters, which is worthy.
“And then we have seen that when it comes to rain, it is very comfortable characteristic, keeps the situation under control, is very fast in execution. And when he does, he is always calm and attractive.
“So this is one, I have to say, Oscar-like weekend. This proves their maturity and their race-craft level as Formula 1 driver.”
The situation in Noris is reminiscent of the person who faced Lewis Hamilton when he was trying to fix a gap for Mercedes team partner Nico Rosberg in 2016.
Hamilton was behind Rosberg in the championship as a result of a series of reliability problems. He was ready to recover the lead with a major win in Malaysia at the end of the year, only to fail to his engine.
He needed to discontinue the difference of 23 points to Rosberg in the last five races to Hamilton.
The German placed himself in a strong position with a win in Japan later next week, and Hamilton was just reduced despite winning the final four races in a line.
Wolf said on Sunday that Malaysia’s retirement had created strains in his relationship with Hamilton.
“Super Hard,” said Wolf. “Because you are letting a driver go down. Now, you can say that it is probably a long season and it was a single phenomenon. But Lewis is working, he is leading the race, he is creating a big difference in the championship and then he will blow up an engine.
“It was hard for him, it was difficult for our relationship.”
However, Wolf emphasized that Noris has much longer to fix the deficit compared to Hamilton.
“The difference is that nine races are left. Surely a blow to the championship, but not impossible. It’s difficult.”
