"After I saw that I wanted to go home and not watch any more TV," Johnson said. "And I didn't want to turn it on this morning."
Police found the 59-year-old Flanagan dead on his property Wednesday. The Maryland medical examiner ruled his death a suicide.
Johnson never played with Flanagan in Baltimore and never managed the Orioles when Flanagan was vice president of baseball operations, but the two were still close friends.
Flanagan recorded the final out at Baltimore's Memorial Stadium in 1991, after which Johnson and other former Orioles took the field one last time.
"It was like a family," Johnson said. "We did just about everything together back in those days."
The pair kept in touch over the years, and Johnson expressed regret at not being able to reach out to Flanagan before his death.
"He was a very settling man. He really had a way -- you knew he was listening to you," Johnson said. "I just wish I had a chance to talk to him. I've lost a lot of people very close to me, and I wish I had a chance to talk to him and cheer him up like he's done for me."