He is currently the hitting coach for the California Golden Bears baseball team, competing in the Atlantic Coast Conference.

[1] A 2005 graduate of Justin-Siena High School in Napa, California, Wallace earned four varsity baseball letters for head coach Allen Rossi.

Among his numerous accolades, Wallace was named a Collegiate Baseball/Louisville Slugger All-American and 2005 first-team All-State (CalHiSports.com) and 2005 California Small Schools Player of the Year.

After his collegiate career, he was picked by the St. Louis Cardinals as their first round (13th overall) selection of the 2008 MLB draft out of Arizona State University.

After his performance at Single-A Quad Cities, Wallace skipped High-A Palm Beach and was promoted immediately to the Double-A Springfield Cardinals.

[9] Wallace was sent to the Triple-A affiliate, the Round Rock Express,[10] for one day and did not appear in a game before being called up by the Astros on July 31, 2010 after Lance Berkman was traded to the New York Yankees.

On September 7 Wallace hit his first MLB career home run off Chicago Cubs pitcher Carlos Silva, tying the game.

[16] On August 24, 2014, Wallace clubbed a walk-off grand slam in the 12th inning to cap a three home run, six RBI game, as the Bisons rallied for a 10–6 victory over visiting Pawtucket Red Sox.

Wallace joined Fernando Martínez (2012) and Marco Scutaro (1999) as the only Bisons to hit walk-off grand slams at Coca-Cola Field.

[17] On December 13, 2014, Wallace signed a minor-league contract including an invitation to major-league spring training with the San Diego Padres.