I've been tracking Luciano Vietto and Dybala as potential false 9's.
If you havn't sold them, Henriquez and Hernandez do really well in the false 9 role. So they are already at your club unless you sold them. Henriquez is a very good goal scorer.
I have Richardo Zichovic, Javier Hernandez and Luka Jovic as my rotating front three.