Lucas was a box-to-box fat frank style midfielder when he won player of the tournament in the U19 world cup.
He's been creatively restrained by Rafa, asked to sit deep more and wasn't amazing at the task. I'd give him one more season's grace. Rafa sees him in training every day, so there must be something there. Maybe he can't bring it to the pitch on a Saturday, but he needs to start doing it. FAST.