Gentry compiled a 158-144 record over parts of five seasons as the team's head coach, and reached the Western Conference Finals in 2010.
Yet, the team missed the playoffs in each of the last two seasons, and has a conference-worst 13-28 record right now.
But wins and losses, at least on a basic level, are not why the Suns and Gentry parted ways Friday.
"You can have a feeling, you can have a time when you feel like you're not progressing," Suns president of basketball operations Lon Babby told Arizona Sports 620's Doug and Wolf Friday. "That there's just a sense this has run its course and that we're out of ideas and we're out of solutions."
Babby explained that holds true for management and coaches, and added that "nobody stays in these jobs forever."
But he saw no need in giving specific details, other than to say it was more of a "feel" than a "specific thing" that led to the decision.