Arsene Wenger believes losing Aaron Ramsey's unique qualities in midfield will be a setback for Arsenal.
The Wales international has signed a pre-contract agreement with Juventus and will officially join the Turin club on July 1, once his existing deal with the Gunners expires.
The 28-year-old has spent the last 11 years in north London – largely under the stewardship of Wenger, who signed the midfielder from Cardiff when he was still a teenager in 2008.
Speaking at the Laureus Sport for Good presentation, Wenger said: "It will be a loss for Arsenal. I must say it will be an interesting move for Ramsey.
"He is a player who is great going forward. His main quality is he can keep the final ball and he makes interesting runs from deep.
"You don't find many players today who can make midfield runs off the ball. It will be an interesting addition for Juventus."
Wenger has been out of work since leaving the Emirates Stadium at the end of last season although he continues to be linked with a host of top management positions – including at Real Madrid and Paris St Germain.
The Frenchman said in October that he expected to return to management by the start of this year although he was unable to shed any light on his future on Sunday.
He added: "My future is unknown – even for me. I enjoy daily life now and I have been travelling a lot recently all over the world.
"I am enjoying a little bit less pressure. And more freedom as well. But I miss the competition."
Thierry Henry and Patrick Vieira – two of Wenger's former players at Arsenal – have had contrasting introductions to European management.
While Henry lasted just three months at Monaco before being replaced recently by his predecessor Leonardo Jardim at the Stade Louis II in January, Vieira has steered Nice to seventh in Ligue 1.
Wenger added: "Both have the qualities to be outstanding managers.
"If you arrive in October, and the team is in a very bad position, you have three months. Because in January everybody starts to become nervous that things could go very badly.
"You have less time when you arrive in the middle of the season. That is what happened to Thierry.
"How he bounces back will be very important. I think he has the quality and desire to make a career, and a career is judged on the longer period.
"I started my job at 33 years of age, I had very promising people around me, and many of them disappeared while some survived. Why? You need luck and (to) work hard. It's always very difficult to predict a career of a manager.
"It depends on the quality of the players and the confidence we get.
"But both have the qualities and I wish they make it a great career.
"It's very good for me to see that players I had continue to share our game with people and develop young players."
