Craig Sager's wife, Stacy, has been by her husband's side throughout his battle against an aggressive form of leukemia.

But a few days before Sager's most recent bone marrow transplant, Stacy was unavailable. She came down with a cold, and doctors told her to stay home to avoid transmitting her illness to Craig, the well-known TNT sideline reporter.

Enter Charles Barkley.

When Barkley heard Stacy was unavailable, he flew to Phoenix to be by Craig's side, defying his own doctor's orders to be with his good friend and colleague. The Hall of Fame forward had hip surgery a few weeks ago and was not cleared to travel. But Barkley told his doctor that he was faced with an emergency.

"Craig Sager is one of the most interesting people I've ever met," said Barkley, who has worked for years with Sager at TNT. "We go to see Sager to cheer him up, and by the time you leave, you're like, 'Is anything wrong with him?' He has the most positive attitude.

"When you go to try and cheer him up, his attitude is so upbeat, he cheers you up."

Sager received a rare third bone marrow transplant Wednesday as the leukemia continues to take its toll. The 65-year-old has battled acute myeloid leukemia since 2014. He remains confident that he will beat the cancer and return to NBA sidelines.

Information from the Associated Press was used in this report.