The veteran Croatia midfielder is in London to sign for Spurs.
Marotta said: â€œIt's shame but he wanted to try the Premier League. We couldn't give him a better offer.
â€œHis choice, in simple terms, was based on a different future to what he has here. Maximum respect for this and a lot of gratitude.
â€œWe will find the right substitute and, in any case, we've already got Robin Gosens who we trust and admire."