Hal, 26, is undergoing further testing and evaluation at the MD Anderson Cancer Center after he was given a preliminary diagnosis from the Texans' team physician.
"My faith in God and the support from my family, friends, teammates and coaches will see me through this difficult time," Hal said in a statement. "I will not let this diagnosis stop me from fulfilling my dreams and I do not want anyone to feel sorry for me. I know how to beat this and I will beat it."
Hal is entering his fifth season in the NFL, all with the Texans. He signed a three-year contract with Houston in August 2017 and played in all 16 games for the Texans last season.
"The news of Andre Hal's diagnosis weighs heavy on the hearts of everyone in the Houston Texans family," coach Bill O'Brien said in a statement. "Andre epitomizes what it means to be a Houston Texan through his leadership, community involvement and team-first attitude. We are confident that Andre's resiliency and infectious positivity, along with treatment and care from the best medical community in the world, will guide him through his recovery. The entire Texans organization is behind Andre and his family during this difficult time and we look forward to his eventual return to the team."
Hal's teammate, David Quessenberry, was diagnosed with non-Hodgkin T-lymphoblastic lymphoma in 2014, but played in his first NFL game last season.