Complex sentence: Allen was the 21st overall round pick in the 2008 MLS SuperDraft, selected by the Los Angeles Galaxy, and he made his MLS debut in Galaxy's first match of the 2008 season against Colorado Rapids on March 29,2008.
Split into simpler sentences: Allen was the 21st overall pick in the 2008 MLS SuperDraft, selected by the Los Angeles Galaxy. Allen made his MLS debut in Galaxy's first match of the 2008 season against Colorado Rapids on March 29,2008.