It's needed to compare them. Amauri played the past year and a half, completelly off-form while leaving the better striker on the bench. Especially in 2008/2009 when Trez needed games to regain match fitness after surgery on both knees. He was consistently overlooked by Ranieri. That continued in 2009/2010, where Trez again, only needed matches...if he just played a few more games instead of Amauri, he would have regained his form and scored even more goals.