The Kenyan's future is the subject of hot debate. Goal understands that Southampton, whose interest has been confirmed by Mauricio Pochettino, have had a £12 million bid accepted but have been joined by Liverpool, Everton and Cardiff City in the race for his signature.
Ledley expects his team-mate to leave and feels that he has the ability to become a huge success in the Premier League.
|33/1||Southampton are 33/1 with BetVictor to sign Gary Hooper from Celtic
"The Celtic fans know how good Victor is and realise we got him at a steal. He can play for a top team in the Premier League, easily. He's got great potential and, if he can get to a top club, it would be fantastic to go up against him in the Champions League in the future.
"Anyone who saw him in that competition last year will know how good he is. I'm surprised none of the top clubs have come in for him but it's early days in the transfer window.
"If Victor goes it will be a massive blow to us. He was terrific in the Champions League for us last season."
Ledley, who spent six years at Cardiff prior to his move to Celtic, also feels that the Bluebirds would be an excellent move for Wanyama.
"The way Cardiff play would suit him as he could be their midfield holding player. He would be a fantastic signing for them," he argued. "They are nowhere near as big as Celtic but it’s the capital of Wales and they're getting more recognition now they are in the Premier League.
"If Victor went there, he'd enjoy it. I have friends who are fans and they've seen him when they're up watching me at Celtic. I know they were excited about the prospect of him going there."