A speedy outfielder, Barker was a Rule V draftee by Houston from the Detroit farm system who spent three seasons as a reserve outfielder and pinch-runner. Over that time, he batted .232 in 235 games with 30 stolen bases. Barker was a member of division champion teams for Houston in 1999 and 2001.

Barker currently works as a scout in the Pacific Rim for the Astros where he has worked to sign pitcher Chia-Jen Lo and infielder Chan Jong Moon.