Posh were hammered 6-2 by Fulham in the FA Cup on Saturday and after selling Aaron Mclean already this month Johnson could be in for a busy few weeks.
He said: "When you're a manager of a football team - my missus will tell you - January is a nightmare and you become a different person as well because you're ducking and diving, trying to bring players in and you're trying not to lose players.
"And you don't take the chairman's calls just in case one of your players has been sold. Of course, some clubs, you have to sell some people. Others, you can keep.
"You just have to be professional about it and make sure the squad you're left with is strong enough when you add two or three.
"Hopefully, we can get back to the league straight away on Tuesday and show what we've learnt by putting up a good performance against Brentford."
Source: PA
Source: PA