In terms of fitness, he is a very fit lad - naturally fit - we will assess him.Garry Monk
The combative midfielder had been sidelined since injuring his knee during the defeat to Aston Villa on 11 February and Blues have subsequently lost the five games he has missed.
"David came back into training today, I am pleased to have him back in the squad," said Blues boss Monk.
"In terms of fitness, he is a very fit lad - naturally fit - we will assess him. We have another training session tomorrow.
"Whether he will be involved at the weekend we will see, it's a day-by-day thing.
"Other than that, it's the same as it was."
Should Davis play against the Bluebirds he will be looking to avoid picking up a yellow card.
He is currently on nine cautions for the season and a further booking on Saturday would see him suspended for two-games, with the deadline for ten cautions resulting in a ban ending after this weekend’s fixtures.
However, Monk says that will not be a factor in his decision whether or not to play Davis if he is fit.
"It's all hands on deck and the most important game is this weekend," said Monk
"I have always thought like that, whatever happens in those situations happens.
"Of course, you plan for it but right now the focus is on this game and whoever steps on the pitch has to be focused on that, not what might come down the line."