I think people overstate how much European football means to footballers. It's usually just code for 'team with more money that will give me more money'.
If European football meant so much to footballers we'd see people queueing up to play for Celtic/Linfied/Basle and, indeed, Fenerbache. But we don't.
They love the coin more than love going to Ukraine on a thursday to play in a competition most of them don't really care about.
Why would Heitinga stay at a team who finish 6th-8th and don't win silverware when he could go to a team who consistently get into Europe, and where he would actually be a starter ?