"Recently I was diagnosed with APL (Acute Promyelocytic Leukemia), the most curable form of Leukemia," Metchie said in a statement released by the Texans.
"I am currently receiving great medical care, am in good spirits and I expect to make a recovery at a later point in time. As a result of this diagnosis, I will likely not be playing football this season. My main focus will be on my health and recovery. Thank you in advance for your support and well-wishes. I cannot wait to come back stronger than ever. God bless."
The Texans placed Metchie on the active/non-football illness list Sunday.
The Texans traded up in the second round, sending three picks to the Cleveland Browns, to select Metchie 44th overall in the 2022 draft.
Metchie had 96 catches for 1,142 yards and eight touchdowns last season at Alabama before tearing his ACL in the SEC championship game in December. Before this diagnosis, he had said he expected to be ready for training camp.
Alabama coach Nick Saban said in a statement Sunday that the Crimson Tide football program will be behind Metchie "every step of the way" and that it is "a blessing that he is in a city known for great medical care and with an organization, in the Houston Texans, who will be with him throughout this journey."