[1] Lo made his professional debut with the High-A Lancaster JetHawks, and also spent time with the Double-A Corpus Christi Hooks, logging a 2.10 ERA in 42 appearances between the two teams.

Lo was invited to Spring Training with the Astros in 2010, but did not make the team and was assigned to Corpus Christi, where he spent the season, posting a 1.80 ERA in 7 appearances.

The following season, Lo split the year between Lancaster and the rookie-level GCL Astros, pitching to an 0.90 ERA with 31 strikeouts in 30.0 innings across 19 appearances.

[4] He made his major league debut on July 31, pitching one scoreless inning of relief and recording his first career strikeout in an 11–0 win over the Baltimore Orioles.

In 17 minor league games with Corpus Christi, the Single-A Quad Cities River Bandits, and the Low-A Tri-City ValleyCats, Lo accumulated a 3.24 ERA.

On December 31, 2019, Lo signed a contract with the Wei Chuan Dragons of the Chinese Professional Baseball League (CPBL).