TNT sideline reporter Craig Sager's leukemia returned last week, his son announced on Twitter on Sunday.
Sager, 63, was diagnosed with leukemia last April and missed almost a year of work to battle the disease. He returned to the sideline on March 5 after being cleared to go back to work.
Sager was scheduled to travel to Omaha, Neb., for the NCAA tournament earlier this month, but later announced that he would not be going after doctors suggested additional testing.
From his son's statement:
"[Sager] is battling his newest set of obstacles, but unlike the first time, when everything was new, there is a blueprint in place and all focus is on one checkpoint at a time. [Sager's] leukemia returned last week and he is undergoing treatment that will be much like this time last year when he got rounds of chemo and prepared his body for a bone marrow transplant.