Per Ryen Russillo on The Bill Simmons Podcast (starts at 68:00 mark), it's "the worst kept secret" in the NBA that Booker wants to leave the Suns.
Booker's name has been floated around in trade rumors since the summer. Marc Berman of the New York Post reported in July that the New York Knicks' hiring of head coach Tom Thibodeaux and president Leon Rose could put them in play for the 24-year-old:
"Since Leon Rose was hired as president, the player to watch out for most is Suns combo guard Devin Booker, according to league sources. If Rose hires Tom Thibodeau, (Karl-Anthony) Towns—a former Rose client—no longer makes sense because of their history. Booker and Towns were Rose clients who played at Kentucky, which means Knicks adviser William Wesley is close to each. Rose has done well with Kentucky standouts because of Wesley."
It's unclear at this point how much interest, if any, the Suns have in shopping Booker around in a potential trade. He still has four years and $130.97 million remaining on the contract extension signed in July 2018.
Booker and the Suns were one of the biggest stories of the NBA's regular-season restart. He averaged 30.5 points and six assists in eight games. The Kentucky alum also had several highlight-reel moments, including hitting the game-winning shot at the buzzer against the Los Angeles Clippers on Aug. 4.
Despite going 8-0 during the eight seeding games and finishing with the same overall record as the Memphis Grizzlies (34-39), the Suns missed out on the play-in game because of tiebreaker rules.
Booker has averaged at least 22 points per game and increased his shooting percentage in each of the last four seasons. He shot a career-high 48.9 percent from the field in 2019-20.