In a letter written to Browns fans at the end of the 2024 preseason, Donovan announced that he would be stepping away from the Browns Radio Network to aggressively focus on his battle with returned cancer. Donovan was inducted into the Class of 2024 Browns Legends on September 22 along with K Phil Dawson, who personally informed Donovan of the news shortly before the ceremony. Donovan's daughter Meghan accepted the Browns Legends jacket on Donovan's behalf during the ceremony.

“He kept it real, but he kept a positive tone,” Dawson said of Donovan’s calls. “He could just always find that balance — authentic, real, accurate, but he was still supportive even when there wasn't much to support. And I know the players appreciated that. I know I definitely appreciated that. He was always quick to try to convey context rather than just letting people focus on a single moment to understand what was going on.

In 2000, Donovan was first diagnosed with chronic lymphocytic leukemia, marking the beginning of a more than decade-long battle with the disease. He underwent a successful bone marrow transplant in the summer of 2011 and monitored the disease over the following years. Donovan announced in May 2023 that he had suffered a relapse of leukemia and would undergo more aggressive treatment.

In September, during the 2023 season opener against the Bengals, Donovan announced that he was taking a medical leave of absence from the Browns Radio Network as he continued his leukemia treatment. He listened to all the Browns games and followed the team as it went through the ups and downs of 2023.

He returned to the radio booth in November for Week 11 of the 2023 season, where he also served as Dawg Pound's captain and smashed a Steelers guitar before kickoff. As he stepped out of the tunnel and in front of the crowd, Donovan broke into a smile as what was now known as Huntington Bank Field erupted in cheers and applause. Minutes after smashing the guitar, Donovan stood in the radio booth with his headset on and announced the Browns' 13-10 victory over the Steelers.

Donovan announced his retirement from WKYC on May 30, 2024. He completed his last broadcast as a sports presenter on June 10th.