Complex sentence: Ruiz joined the major league roster on opening day 2007 "for good", having completed eight seasons in the minor leagues; he ultimately "grabbed hold of the top job (as starting catcher) and never let go".
Split into simpler sentences: Ruiz joined the major league roster on opening day 2007 permanently, having completed eight seasons in the minor leagues. He ultimately "grabbed hold of the top job (as starting catcher) and never let go".