The Brazil international fractured a metatarsal in his right foot early in City’s 2-0 Premier League victory at Bournemouth on Monday.
The 19-year-old limped off after just 15 minutes at the Vitality Stadium and, despite manager Pep Guardiola expressing hope the injury was not serious, fears were confirmed following tests yesterday morning.
The forward will undergo further assessment to determine the full extent of the problem but such injuries typically lead to a lay-off of six to eight weeks. Some reports have even claimed Jesus could be sidelined for up to three months.
Such a scenario would all but rule Jesus out for the remainder of the season.
A statement from the club read: “Manchester City can confirm Gabriel Jesus suffered a fractured metatarsal during the 2-0 win over Bournemouth on Monday night.
“He will undergo further examinations in the coming days to establish the extent of his lay-off.”
Jesus was pictured on Tuesday afternoon wearing a protective boot and walking with crutches.
The injury is an undoubted blow for City, who resume their Champions League campaign next week when Monaco visit the Etihad Stadium for the first leg of their last-16 tie.
Jesus has made an immediate impression since joining City in a £27m (€32m) deal from Palmeiras in January.
He has scored three goals in his five appearances, including an injury-time winner against Swansea, and so impressive were his performances he was being selected ahead of top scorer Sergio Aguero.
That situation had led to speculation over the future of Aguero, who has scored 154 goals for City since joining the club in 2011.
Aguero, 28, replaced Jesus at Bournemouth and forced the Tyrone Mings own goal which secured City’s victory and lifted them to second in the Premier League.
The Argentina international is now likely to continue leading the line, although City are not in Premier League action again until March 5. They travel to Huddersfield in the fifth round of the FA Cup this weekend.
Meanwhile, former Manchester City manager Manuel Pellegrini believes his successor will now have a good appreciation of his achievements at the club. Pellegrini won the Premier League title in 2014 and two League Cups before making way for the arrival of Guardiola last summer.
After winning 21 trophies in seven years with Barcelona and Bayern Munich, Guardiola arrived with a huge reputation but he is taking time to settle at City.
City have been inconsistent for large spells of the season and are currently eight points behind Premier League leaders Chelsea.
: “I think he (Guardiola) values my work a little more in those three years. It is not easy to win the Premier League.
“Perhaps many thought that with the arrival of Pep, they would win the Premier League with 15 points difference, and no, in England this is not the case.”
City had pursued Guardiola for years before finally landing the Spaniard. When it became clear City would get their man, it was Pellegrini himself who put an end to speculation by announcing, last February, he would leave at the end of the 2015-16 campaign.
Given that form subsequently deserted his side, Pellegrini accepts that was a mistake.
The Chilean, who is now in charge of Hebei China Fortune, said: “If you ask me if today I would have done otherwise. I say, yes, I would have waited until the end of the season. It was my initiative but I would do it differently.
“But there was so much rumour. It bothered me.”