"Everything was agreed with Fulham, but the player decided he did not want to leave,"said Ridsdale
"That was disappointing, but we move on to the next stage and there are good quality options.
"We will still be bringing in the midfield player we need."
Ridsdale confirmed Cardiff will now look to bring in a new midfielder on loan when the window reopens next week.
He added: "We have four or five other high quality targets and now have a week to move.
"The two-week international break gives us the time we need."
It's also been reported this week that City asked Arsene Wenger if they could have Aaron Ramsey back on loan. Non was the reply from the Frenchman.