The Welsh midfielder expects that Forrest will have a massive role to play on Wednesday night as Celtic try to come out of Turin with their pride still intact.
After a difficult season that has been mired in injury, Forrest is edging his way back to full fitness. Judging by his contribution during Saturday's 2-1 win over St Mirren in the quarter-finals of the William Hill Scottish Cup, he is getting close to the standard that he set himself last season.
"He's definitely one of the best players I have played with and definitely one of the best young players I've seen," said Ledley.
"He really does give us something different. He is young, he is exciting and the sky is the limit for him.
"It's great having someone like that in the team because you know that if you can get the ball to him then he is always capable of making something happen.
"We have a massive game on Wednesday night against Juventus now to look forward to and I am sure that he will feature hugely in the manager's plans."
Celtic go to Turin knowing that, in reality, it is game over.
The Italians have a 3-0 lead from the first-leg to protect but Ledley has insisted that Celtic will go there looking to make their point.
"It has been a tremendous European season for us and we don't want it to end on a real downer," he said.
"I think a lot of us felt that the scoreline from the first-leg flattered Juventus.
"Don't get me wrong, I was impressed with them.
"They were very organised, very physical, their technique was excellent, they had a game plan and they were clinical, but in many respects it is one of the best games I felt we had played in the Champions League all season.
"I don't think we can afford to go into the game thinking that we have given up.
"We are professional footballers, we know what it means to represent the club and we want to give a decent account of ourselves – and to show that the first-leg result was a bit of a fluke."
Scott Brown is currently out of the side as he prepares for surgery to cure an abductor problem, and Ledley has taken the captain's armband in his absence.
Brown has been nursed through the season and Ledley, like his team-mate, at one stage seemed to be suffering similar symptoms to Brown's original hip issue.
However, he has revealed that he is playing pain-free now and there is no likelihood of him also requiring to go under the knife at any stage.
"I had a bit of a blip this season and I was rested a little," he said.
"I got an injection into the injury and since then I've never really looked back.
"I'm playing without any discomfort and that is probably reflected in the way I've been playing in recent weeks.
"I'm moving freely, I don't feel restricted by it and at the minute there is absolutely no concern about my health or fitness whatsoever.
"But I do feel for Scott. It is a boost for me as a Welshman because he is definitely one of Scotland better players and he won't be there later this month but as a team-mate we definitely miss him when he's out.
"I am relieved that mine wasn't anywhere near as severe."