Saturday's showdown at the Riverside Stadium could hold the key to European qualification.
Seventh place in the Barclays Premiership will be good enough for a UEFA Cup place and we are in pole position having nudged ahead of Middlesbrough on goal difference after beating Villa 5-1 on Sunday.
We travel to Teeside level on points with Manchester City and Villa still in the shake-up for seventh place.
"This is a massive game and what we play football for," said skipper Ledley. "It's a real test of character to see how far we've come.
"We've a young squad and perhaps people might have thought it was too soon for us but we've shown that we're good players, we'll get better together and good things can happen from here.
"There were a lot of changes in the summer, new faces on the playing side and staff as well. There was a fresh feeling about the place.
"Martin has also made a difference - he's showed his desire and the players are the same now.
"We know we're that we're a young squad and it's great. Fredi Kanoute was the oldest out there on Sunday and he's only 27! We're all hungry and it's been working well."
Ledley believes the five-star show against Villa could be significant in the final few days of the season. "It was a great performance and one we needed. It showed everyone how much we want to qualify for Europe and we've sent a message out with that result.
"No-one expected us to score five against Villa but it's happened, put us one goal ahead of Middlesbrough and that could be vitally important at the end of the season with how tight it is at the moment."
Ledley King says the huge clash at Middlesbrough is the type of game all footballers love to be involved in.