Heaney, from Oklahoma City, pitched for the Cowboys from 2010-12. He was the 2012 Big 12 Pitcher of the Year, posting an 8-2 record and 1.60 ERA, before becoming the ninth overall pick in the subsequent MLB Draft.
The Roberto Clemente Award, named after Hall of Famer Roberto Clemente, is given to the player "who best represents the game of baseball through sportsmanship, community involvement and positive contributions, both on and off the field," according to the award's site.
Each MLB team names a nominee before fans vote on the winner. To vote for Heaney, fans can use #VoteHeaney on social media starting Wednesday.