Marshall made his major league debut against the St. Louis Cardinals on April 9, 2006, recording a no-decision.Seligman, Andrew, Chi Cubs 8, St. Louis 4 , Yahoo! Sports, Retrieved on May 23, 2007 In that game he yielded a two-run homer to Scott Rolen in the first inning before settling down to pitch solidly for 4+ innings. The Cubs trailed 4-3 in the late innings, but rallied to win on a Michael Barrett grand slam in the eighth inning. He earned his first major league win on April 14, 2006, against the Pittsburgh Pirates.Robinson, Alan ,Chi Cubs 11, Pittsburgh 6 , Yahoo! Sports, Retrieved on June 6, 2007 Marshall indicated his pleasure with the start. He stayed in the starting rotation for the first half of the year before suffering a strained left side muscle.Fendrich, Howard, Washington 7, Chi Cubs 3 , Yahoo! Sports, Retrieved on June 6, 2007 Marshall left the rotation after a crushing loss on July 16 in which the Cubs gave up two grand slams in one inning, blowing a 5-2 lead in the 6th inning against the New York Mets.Muskat, Carrie, A grand Mets endeavor , MLB.com, Retrieved on April 3, 2008 In 19 starts, Sean posted a 5-8 record with a 4.98 ERA. On September 2, Marshall returned to the Cubs' rotation, but posted a loss against the San Francisco Giants. During the game, he gave up career home run #728 to Barry Bonds in Chicago.Gano, Rick, San Francisco 4, Chi Cubs 2 , Yahoo! Sports, Retrieved on June 6, 2007 In his remaining four starts, Marshall struggled, and completed six innings only once.
