The Etihad Stadium hosts the 187th Manchester derby on Sunday, when the Red Devils will look to boost their top-four chances against the Premier League leaders.
United come into the match bruised by last weekend’s 0-0 home draw with Watford, where their recent profligacy in front of goal continued on an afternoon when they had 22 shots without scoring.
Star turn Cristiano Ronaldo has only scored once in 10 games but Rangnick believes things will soon turn for the team, with Edinson Cavani set to return and Rashford backed to shine in the coming weeks.
“A few things that have happened in the last couple of weeks, or two months couldn’t have been foreseen by anybody,” he said of United’s goalscoring issues, appearing to nod at forward Mason Greenwood’s club suspension.
“Now, with Edinson at least being available for the game and the upcoming games, we have other options.
“With Marcus Rashford, we have another player who I will insist and continuously be behind him and with him, to develop him.
“We have achieved that with quite a few other young players in the past and I don’t see why this should not happen with Marcus.
“He’s got abundant talent, he’s got the pace, he’s got the physicality, he’s got everything that you need for a modern striker, no matter if he’s playing from the wing or in the centre.
“I will put all my energy into that, to help him to take the same pathway that other players did in the last three months.”
Rangnick’s comments suggest Rashford could start at City, but Cavani will almost certainly be reduced to a role off the bench after five games out with a groin injury.
“Well, it’s good to have him back,” he said. “We have one more alternative in a central attacking position but he has been out for three weeks.
“That’s also something we have to bear in mind. I don’t think he could play for more than, I don’t know, half an hour.
“He’s ready for that, for coming on as a sub but I don’t think he can be in contention to start that game.”
Another player that returns to contention is Scott McTominay.
The 25-year-old missed the Champions League last-16 tie at Atletico Madrid through illness, which also saw him miss the Watford match and Rangnick has revealed it had quite an impact on the midfielder.
“Important to have him available,” the interim boss told MUTV. “He’s been training the whole week.
“He’s been out one week only but he was really seriously ill and lost some weight.
“I think he could be in contention for the starting XI but I will decide on that (Saturday) after the last training session.”