Mike Welch
... that the New York Mets traded Mike Welch to the Philadelphia Phillies for Hector Mercado, a player who was drafted and traded the same day, only for him to play against the Mets on his major league debut?
... that the <a href="./New_York_Mets" id="mwuQ" rel="mw:WikiLink" title="New York Mets">New York Mets</a> traded <b id="mwug"><a href="./Mike_Welch_(baseball)" id="mwuw" rel="mw:WikiLink" title="Mike Welch (baseball)">Mike Welch</a></b> to the <a href="./Philadelphia_Phillies" id="mwvA" rel="mw:WikiLink" title="Philadelphia Phillies">Philadelphia Phillies</a> for <a class="mw-redirect" href="./Hector_Mercado" id="mwvQ" rel="mw:WikiLink" title="Hector Mercado">Hector Mercado</a>, a player who was drafted and traded the same day, only for him to play against the Mets on his <a href="./Major_League_Baseball" id="mwvg" rel="mw:WikiLink" title="Major League Baseball">major league</a> debut?