I generally don't like to see top footballers shoehorned into a different position to fill a team's needs. One a one-off, sure, but not as a going forward plan. Martinez is a CB, full stop.
But back to Willy, what a tremendous talent the boy is. Whoever is responsible for the care of our young players better be equipped for the job as we've seen several of our outrageously talented young players over the years gone headsgone in one way or another -- Martial, Greenwood, Sancho and in all honesty, Rashford as well. The issue with Antony isn't so much that he went headsgone but that he was never that great of a talent to begin with.