The defender suffered a knee injury during the Blues' 3-1 win over Sheffield Wednesday last weekend and the early prognosis suggests that he could be sidelined for a while.
Cotterill said that he is considering all options when it comes to filling the left-back void, including a new signing or playing another of his defenders out of position.
"It is an option. But it's hard to find one of them. We'll have to wait and see. We need the results back off Jonathan first of all," he told reporters during a press conference.
"But then how long does it take to get that player up to speed and have you got players that can potentially play out of position that have played in that position before?
"Put it this way, we don't have a lot of options, so the option that I go with will, I hope, be the best option in the coming games."
Birmingham were in FA Cup action on Tuesday evening, going down 4-1 to Premier League Huddersfield Town in the fourth round, after extra time.