The Manchester United manager claimed Ronaldo was being 'systematically targeted' by opponents after Tuesday's UEFA Champions League draw with Villarreal.
His comments came after Villarreal full-back Joan Capdevila was sent-off near the end of the 0-0 draw for a particularly vicious knee-high tackle on the 23-year-old.
As well as such tough challenges on the pitch, Ronaldo is also subject to numerous terrace taunts off it.
But Ferguson believes the prospective Fifa World Player of the Year has the courage to get on with things.
Ferguson said: "I think Cristiano is coping well.
"Let's be honest, nobody likes getting whacked all the time. But Cristiano has the courage to get on with it. He carries that mantle well."