nobody is untouchable, not even EP40, BB6, or BH53.
they're all tradeable, just a matter of the "right" offer being made.
with that being said, Virtanen is a valuable piece to the team. He may not be a player of EP40's calibre, or even BH53's calibre, but he's a solid contributer on the team already, at 22. I see Virtanen continuing to improve, and becoming a 40-45 point player, who's physical and difficult to play against.