Sherwood lauded City after Manuel Pellegrini's men won 5-1 at White Hart Lane to go top of the Barclays Premier League ahead of Monday's contest with Mourinho's side at the Etihad Stadium.
Mourinho believes City will find their true level in European competition, where they face Barcelona in the Champions League first knockout round.
"You will see (how good City are) in the Champions League. You will see in a couple of months."
Mourinho also suggested City have been fortunate game-changing decisions have gone their way this season - something he described as a coincidence but was at pains to point out as Mike Dean prepares to referee Monday's match.
"They are lucky," Mourinho said. "The reality is they have many crucial decisions in their favour.
"Against Liverpool, the (Raheem) Sterling 'goal'. The penalty on (Luis) Suarez. Against Newcastle the goal that is a clear goal.
"Against Tottenham, (Michael) Dawson's goal, the penalty, the (Danny Rose) red card. They are having everything.
"I repeat, because I don't want to be misinterpreted (it is) just pure coincidence.
"The referees, they try to do their best and sometimes they make mistakes and normally during the season the mistakes are split between teams.
"In their (City's) case, they have everything in their favour."
City have a 100 per cent record from 11 home matches, averaging more than four goals a game, and are a fearsome prospect for most visiting opponents.
Mourinho is unfazed and, unlike in goalless draws at Manchester United and Arsenal, says Chelsea go to City seeking victory.
The Portuguese, who was frustrated by West Ham's negative tactics in Wednesday's 0-0 draw, said: "We're not going to change our philosophy. Chelsea always go to try and win."
City, who are three points ahead of third-placed Chelsea entering the match, are Mourinho's favourites for the title in a season of rebuilding for the Blues.
He will be more optimistic next term.
"Next pre-season, day one, I will say we are candidates to win the Premier League," he said.
"This season, the speech is we are candidates to win the next match. It doesn't matter where, it doesn't matter the opponent.
"We're just trying to win. I tell you now, before Man City... I will tell you before the Newcastle game next week, and then West Brom. I will repeat this."
Mohamed Salah, who signed from Basle, could be included in the squad for his debut, but striker Fernando Torres (knee) remains out.
Zouma signed a five-and-a-half-year contract from St Etienne - where the 19-year-old remains on loan for the rest of the season - to become Chelsea's fourth and final January signing after Nemanja Matic from Benfica, Salah and Bertrand Traore, who immediately was sent on loan to Vitesse Arnhem.
Chelsea moved for Zouma now as sides were lining up to recruit the defender, who could spend next season on loan.
Mourinho has spoken of building a team for the next decade and Zouma's acquisition fits with his brief of recruiting young players full of potential.
"We like the profile. We think he's very much adapted to the Premier League," Mourinho said.
"In almost every position, we have the present and also the future."
Mourinho told those surprised that he did not recruit a striker in the winter window that one will arrive in the summer.
He added: "We don't sign a striker now to be an emergency plan to try to score half a dozen goals. That's not the right approach.
"We're waiting for the summer to do the right thing in that area, to do exactly what the team needs.
"No deals (are in place). We just know basically what we want, and we know what we want is impossible to get in this transfer window."
- Sports & Recreation
- Premier League
- Kurt Zouma