A former first-round pick of the Astros in 1995, the Texarkana native got his debut with the Astros in 2000. Unable to secure a role on the Astros' staff, he was sent the next year to the Pirates in a deadline deal for reliever Mike Williams. While in Houston, McKnight started nine games and posted a 5-1 record with a 3.91 ERA. For his full career, he compiled a 7-7 mark with a 4.63 ERA in 21 starts.