Click on a thumbnail to go to Google Books.
The Warrior Heir (original 2006; edition 2007)
References to this work on external resources.
Wikipedia in English
Amazon.com Product Description (ISBN 0786839171, Paperback)
Before he knew about the Roses, 16-year-old Jack lived an unremarkable life in the small Ohio town of Trinity. Only the medicine he has to take daily and the thick scar above his heart set him apart from the other high-schoolers. Then one day Jack skips his medicine. Suddenly, he is stronger, fiercer, and more confident than ever before. And it feels great—until he loses control of his own strength and nearly kills another player during soccer team tryouts.
Soon, Jack learns the startling truth about himself: He is Weirlind; part of an underground society of magical people who live among us. At the head of this magical society sit the feuding houses of the Red Rose and the White Rose, whose power is determined by playing The Game—a magical tournament in which each house sponsors a warrior to fight to the death. The winning house rules the Weir.
As if his bizarre magical heritage isn’t enough, Jack finds out that he’s not just another member of Weirlind—he’s one of the last of the warriors—at a time when both houses are scouting for a player.
(retrieved from Amazon Mon, 30 Sep 2013 13:27:27 -0400)
After learning about his magical ancestry and his own warrior powers, sixteen-year-old Jack embarks on a training program to fight enemy wizards.
(summary from another edition)