Haaland ruled out for up to seven weeks: Guardiola
The prolific 24-year-old Norwegian was injured in Sunday's 2-1 FA Cup quarter-final win at Bournemouth.
Having just scored his 30th goal of the season to level the tie, he was then hurt in a challenge with Bournemouth midfielder Lewis Cook.
City said in a statement on Monday that they expected the forward would be fit in time to play before the end of the season, including the FIFA Club World Cup.
"They told me the doctors between five and seven weeks, so hopefully at the end of the season we can be ready," Guardiola said on Tuesday.
"We don't have another player with his skills or his specific qualities," he added. "We know that, but we have to adapt.
"For many years we have played in different ways up front. It depends on the quality of the players. We are going to try to find a solution."
City are currently fifth in the Premier League and battling to secure a spot in the Champions League next season.
Guardiola's side host struggling Leicester on Wednesday and face Manchester United at Old Trafford on Sunday.