Roberto Mancini does not expect to replace Mario Balotelli before the end of the transfer window on Thursday.
The Italian striker, 22, is due to finalise a move to AC Milan on Wednesday for an initial fee believed to be 22m euros (£19m).
It leaves Mancini with only three recognised strikers but the manager doubts he will sign a replacement.
"We only have two days and it is difficult to buy a good player in this moment," said Mancini.
City have been linked with big-money moves for Napoli striker Edinson Cavani and Atletico Madrid's Radamel Falcao in the January transfer window, despite Mancini's insistence that he will not be able to replace Balotelli before the deadline.
However the manager admits that the loss of Balotelli, who signed for City for £24m in 2010, lessens his options as City look to close the four-point gap on leaders Manchester United, who also have a game in hand.
"It is difficult because I lost one important striker and that could be important in the next 14 games," Mancini said.
"But it is important for Mario - to be back in Italy, back with his family and to play for Milan."
The 2011-12 season was arguably Balotelli's most productive as he netted 20 goals in 40 appearances and provided the crucial assist for Sergio Aguero to score the title-clinching goal against QPR in May last year.
He has not featured as much this season, with Mancini preferring to play Aguero, Carlos Tevez and Edin Dzeko, and he was involved in a training ground altercation with his manager at the beginning of the month.
However, Mancini says the two have parted on good terms and said he hopes to see the player realise his potential in Serie A.
"We are sorry because we love him like a guy and like a player," said Mancini. "We did well with him - we won the FA Cup, Premier League and Community Shield, and it's clear we are sad at the moment.
"I hope Mario can improve and can show he is ready because if he works hard he can continue his growing and can become one of the best players in Europe."
Balotelli's time in Manchester has been dominated by constant headlines, with the striker struggling with his discipline on the pitch.
In his first season at Manchester City he scored 10 goals in 28 appearances, but was also sent off twice - against West Bromwich Albion and Dynamo Kiev.
He had similar problems last season, picking up 11 yellow cards and being sent off in Premier League games against Liverpool and Arsenal - the latter prompting Mancini to suggest he would be willing to sell the striker.
And Mancini, speaking after his side's 0-0 draw with bottom club Queens Park Rangers on Tuesday, joked that journalists will be sad to see the player leave the Premier League
When asked if he will miss Balotelli, Mancini said: "Yes. I think that he will miss me and all the journalists. For you [journalists], he was very important."