4 Cardinals placed on Top 100 Prospects list
Seattle Mariners send top prospect Tyler O'Neill to St. Louis Cardinals for Marco Gonzales - ESPN
Goold: Cardinals use recent trades to fortify system, maintain their rank
Seattle Mariners, St. Louis Cardinals swap Tyler O'Neill, Marco Gonzales
Cardinals acquire Mariners top prospect Tyler O'Neill for Marco Gonzales
Where Seattle Mariners could look if they decide to trade for a bat - Seattle Sports
Tyler O'Neill Statcast, Visuals & Advanced Metrics, MLB.com
Tyler O'Neill Stats & Scouting Report — College Baseball, MLB Draft, Prospects - Baseball America
Mariners' Marco Gonzales saw some strange things in Boston - Seattle Sports
St. Louis Cardinals: Cardinals trade Mike Leake to the Mariners
An Unpopular Trade Paying Off In Seattle - MLB Trade Rumors