Tevez, who missed a penalty against Wigan last Saturday, was back on the bench for the midweek Champions League game against Napoli.
Mancini insists that Tevez, who failed to secure a summer move away from the club, must accept the situation.
"In this moment there are players that are better than him but Carlos is here training," he said.
"Carlos will have a chance to play. I don't know if he is happy but every player that can't play is not happy. This is normal.
"He will have his moment."
The form of fellow strikers Edin Dzeko and Sergio Aguero, who have scored six league goals apiece so far this season, mean that the 27-year-old Argentina international's chances have been limited, while Mario Balotelli has also played just one league game.
But Mancini believes his free-scoring side still need to be more ruthless in front of goal than neighbours and arch-rivals Manchester United, who have scored 18 goals - three more than City - in their first four Premier League games.
When City underlined their title credentials with a 5-1 win at Tottenham last month, United bettered them with a 8-2 victory over Arsenal.
Mancini's men impressed again by beating Wigan 3-0 last week, only for United to hammer Bolton 5-0.
The Italian said: "Man United are a top team - they have been used to winning for a long time. They have strong players.
"When they played against Arsenal, when they scored two or three goals, they continued trying to score.
"We need to have this mentality. If we have a game like Tottenham where we can score, we need to continue to try to play."

The fight, Adams' second as a professional and first in her home city for 20 years, will be over four three-minute rounds, rather than the usual two-minute rounds for women.
The flyweight voiced her frustration with two-minute rounds after beating Virginia Carcamo last month.
Salazar, 18, has lost once in six professional contests.
Adams, 34, says the extra minute in each round will give her a chance to try out things she has learnt in the gym.
She said: "I had two minutes to find my rhythm, distance and take out my opponent. It's not enough time.
"I found, by the end of the rounds, I needed a couple more seconds and it would be over.
"Now we have three minutes, I'm able to relax more, establish the jab, find the rhythm properly and really get in the swing of things."
On the same card, WBC international featherweight champion Josh Warrington defends his title against Spain's Kiko Martinez.

In March, the ICAO issued an alert on Thailand's aviation body after a safety audit revealed that it failed to adequately oversee its airlines.
The move led to a ban on new flights to China, Japan and South Korea.
Thai officials had then submitted plans to deal with the concerns in March.
But, the ICAO "red flagged" the country's body on Thursday for failing to solve the issues within 90 days.
Thailand's aviation sector joins 12 other developing countries, including Nepal and Sierra Leone, that have been downgraded to Category 2 from Category 1 by the organisation for its safety standards.
An audit in January by the United Nations body had found that Thailand's aviation authority had a shortage of technical officers and issues with certifying the transportation of hazardous goods.
The warning meant the country's airlines had to cancel flights and refund or alter thousands of air tickets.
The country's flag carrier, Thai Airways, said in a statement that it followed the "highest safety standards" in all operational areas, despite the red flag from the international regulator.
Manchester City manager Roberto Mancini says Carlos Tevez must wait for his chance to get back into the team.
[NEXT_CONCEPT]
Britain's double Olympic champion Nicola Adams will face Mexico's Maryan Salazar in Leeds on Saturday.
[NEXT_CONCEPT]
The International Civil Aviation Organization (ICAO) has downgraded Thailand's aviation standards, "red flagging" the country for failing to address safety concerns.