Ralf Rangnick said he has gone from thinking Manchester United were the "worst team he has ever coached" after the derby defeat to Manchester City to dreaming about winning the Champions League following victory over Tottenham on Saturday.
Ronaldo's performance at Old Trafford came three days before United host Atletico Madrid in their Champions League last-16 second leg and the 37-year-old's form prompted questions about whether he could win the tournament for a sixth time this season.
"This is what I also like about this club," United's interim manager said.
"On Sunday, I almost felt like we were at a funeral, that it was already dead. I felt like it's the worst team I ever coached. And after the 3-2 win against Tottenham we're discussing about our chances to win the Champions League. Ask me that question should we reach the final of the Champions League, then you can ask me that question again."
United face Atletico on Tuesday after drawing 1-1 in Spain. Victory over the Spanish champions at Old Trafford would guarantee only their third appearance in the quarterfinals of the Champions League since reaching the final in 2011.
"With Scotty, I hope so but he had some muscular problems with his calf," Rangnick said.
"That's why we decided not to play him [against Tottenham], because Scotty quite like Fred, he is only valuable if he can perform with 100 percent of his physical capacity and rather than playing him at maybe 80 percent and take the risk that he will be out for Tuesday, we decided to not play him.
"Luke hopefully will be back in training and Bruno we will have to wait and see until Tuesday. This will probably be a last-minute race with him.
"We have to be careful with COVID tests. David [De Gea] was the same.
"David was out [against Spurs], he was not supposed to play but then it turned out that he first fast test was false.
"He took another one or two quick tests then a PCR test and that was negative. I only decided on Saturday morning that he was going to play."