After the doctor found a heart arrhythmia, she advised him to retire.
"The kind of arrhythmia that I have can be fatal when combined with stress," Lyman said. "If I stayed coaching, the way I coach, I'd probably pass out and die of a heart attack on the court."
For now, he'll still be a part of West basketball, though in a less-demanding capacity. He is passing the baton to Mike Matheson, a graduate and current teacher at East High School, and will be assisting at team practices.
"I felt like if I quit cold turkey, that might be more stressful than anything," Lyman said. "Mike [Matheson] is a good friend, and I support him. I'm still going to come to the gym, work and help kids out. That's exercise, not stress."
Matheson will be inheriting one of the best programs in the state, though also one that lost tremendous talent in graduated seniors Tyrell Corbin and Gatete Djuma, two players who have gone on to play at the next level.
"I'm very happy with the [current] talent level. Normally, the graduating seniors would be a cause of concern, but for me, I've been pleasantly surprised by some of the players that have emerged the last couple of weeks. I'm not predicting we'll make a run at Lone Peak, yet I know that we'll be competitive."
West will be led by three seniors. Lennon Coley is returning with varsity experience, while Devin Price and Zach Floisand are players to watch, Matheson said. He'll also have two junior contributors in Gordon Vetas, a long shooter who'll play from the wing, and Holani Olive, a post player who will fill up the paint.
Matheson said the players were surprised by Lyman's retirement but took the news in stride.
"I've been very pleased by how they've responded," Matheson said. "Overall, it's an aggressive, tough, West High group of kids. They didn't cry too much. They went right down to business."
Lyman believes the program is in good hands.
"Rebuilding is a dirty word for us," Lyman said. "We feel we're pretty good every year. It's a young team, but there's nowhere to go but up. There's no pressure on Mike."
"Neither of us is going to stress out this year," Lyman added.