The Eagles currently lie three points outside the bottom three in 17th place.
"It's a fantastic record he's got, and since he's been here he's done magnificently. He's got us working hard as a unit and as a team," Ledley told the Croydon Advertiser.
"We work with him every day and you can see he's very determined to keep us up - and so are we.
"We all work hard for each other and that's what you need. You need that dedication and hopefully we can fight right until the end."
Palace travel to Newcastle United on Saturday.