Ledley's return added to the recovery from injury of Ross McCormack and Jay Bothroyd gives City more attacking options. There is one injury concern. A foot problem may rule out Eddie Johnson.
Swansea are without Jordi Gomex through suspension, and Ferrie Bodde through a long term injury. It's likely they will be without Leon Britton as well.
"Leon is a very big doubt," said manager Roberto Martinez.
"And the fact he was not involved against Coventry showst he extent of his injury. It is a back problem, and he is 90 percent out of the derby. But this is just another test for our squad."
Ledley expects Cardiff to perform better than when the teams met in the Carling Cup in September. Swansea won that game 1 - 0.
"We gave away to many stupid free-kicks in key positions." he said.
"Their goal was from a free-kick and I got my booking from charging in and had to be careful for the rest of the game and that affected me and the way the team wanted to play.
"It is a case of keeping our heads and learning from our last encounter.
"But one thing is for sure we will be a different proposition than last time, we all owe ourselves, the supporters, and the club a better game then in September."
Dave Jones has just to get final approval from the officials.
"We've had a cast made for his finger," confirmed the Bluebirds boss.
"We need the all-clear from the referee, which we know we will do, then Joe will be back in the squad.
"He is fit, his his legs and lungs are okay but it's just his finger at this moment in time.
"We spoke to the match referee and he is quite happy to get a local referee in to have at it to give us the all-clear.
"It's only going to be more of a cushion just in case someone bumps up against him it's not going to hurt him.
"He has no fears, it's the index finger and when you're running your fist is normally clenched anyway so he should be okay."