The Citizens are hoping to improve the quality and depth of their squad as they look to secure Champions League qualification for next season.
Given the are 14 points adrift of Liverpool, the league title may have already gone.
Asked about this month, Guardiola told reporters: "I don't know right now. It is not easy and will not be easy.
"Maybe we will sign or maybe we won't sign anyone.
"The club has to be wise. To add players in the situation that we are in when there are many consistent injured players then the club has to do it, but I don't know if it will be possible to do it."
He also admitted that 22-year-old James McAtee deserved more playing time.
Guardiola added: "Yes. It made me believe that he should have more minutes.
"But he is young and there are a lot of games to play. I have big respect for how he behaves in the locker room."