Marshall was fighting for the fifth starting pitcher spot for the 2007 Chicago Cubs organization. After rehabbing from a sore shoulder he started the season in Des Moines, Iowa, with the AAA Iowa Cubs. On May 22, Marshall was promoted to the Cubs' starting rotation by manager Lou Piniella replacing Ángel Guzmán. Marshall struggled to get run support in his first two starts and fell to 0-2. On June 3, 2007, he claimed his first win of 2007 by matching a career high 8 strikeouts by leading the Cubs to a 10-1 victory over the Atlanta Braves.