Simplify the following text for a Grade 8 native English-speaking person.
Original: Birch is signed with World Wrestling Entertainment ( WWE ) , and works as a trainer in Florida Championship Wrestling , WWE 's developmental territory , as Joey Mercury .
Simplified: Birch wrestled in the indies with the name Joey Matthews , and is now working with World Wrestling Entertainment ( WWE ) on its SmackDown ! show , where he wrestles as Joey Mercury .