Ferguson told BBC Radio Cambridgeshire: "It's a shape which suits our most creative players, particularly George Boyd, so we may look at it again.
"When we've got the ball the rotation in midfield is the key."
Posh play Newcastle on Tuesday in the League Cup having already dispensed with Wycombe and Ipswich.
Ferguson must decide whether to start with a similar side to the one which played the second half of the Reading win.
Dean Keates and Lee Frecklington came into the team in place of Toumani Diagouraga and Chris Whelpdale.
Whelpdale has only just returned from a ten week injury lay-off and his fitness may be a factor in what Ferguson decides to do against Newcastle.
emp_load.getEmpEmbeddedParams("emp_8269015");"I've always felt that three of four games after a big injury, it's time to take a player back out again, so it will be something to look at," he said.
Ferguson has made clear his desire to progress in the League Cup this season and Posh have already gone further than in the past two years.
Newcastle arrive at London Road having enjoyed a good start to their league campaign, and Ferguson knows they have plenty of quality players.
"They've got a bit of momentum going and it doesn't surprise me given they have perhaps the best support in football," he said.
"But we're looking forward to it because these are the sorts of games you want to be playing."