The move only makes the 25-year-old a restricted free agent, so the possibility remains he could land with a new team this summer. He could also sign the qualifying offer, which would pave the way for him to be an unrestricted free agent in 2022.
Nunn should have plenty of options following a solid 2020-21 campaign.
Building on an All-Rookie season the year before, he averaged 14.6 points, 3.2 rebounds and 2.6 assists. He also shot 48.5 percent from the field and 38.1 percent from beyond the arc.
One of Nunn's best outings came in a 96-94 victory over the Los Angeles Lakers on Feb. 20. He finished with 27 points on 10-of-14 shooting, including 5-of-6 from beyond the arc, while adding five rebounds, three assists, two steals and one block.
The 6'2" guard has been another of Miami's player development success stories
Nunn went undrafted in 2018 likely in no small part to him pleading guilty to a 2016 misdemeanor battery charge after he was accused of choking a woman he was dating. He was later dismissed from Illinois.
His on-court displays have been emblematic of a franchise that continually maxes out the talent on its roster following the end of the Big Three era. Shortly after landing with the Heat in 2019, Jimmy Butler spoke highly of him in an interview with Yahoo Sports' Chris Haynes.
"Look at the motherf--ker K-Nunn," Butler said. "Look at him. He's got so much of me in him that it's scary because his confidence continues to grow."
Nunn's size might limit his ceiling, especially since he's neither an elite shooter or playmaker. His frame also presents some problems on defense because a player can only do so much to compensate for any difference in height and weight.
Nunn was a respectable 21st among 2-guards in ESPN's defensive real plus-minus (plus-0.63), but opposing players shot 60.4 percent inside 10 feet and 69.0 percent inside six feet when matched up against him, per NBA.com.
Restricted free agency can always be a bit of a crapshoot because it only takes one team to covet a player and throw a massive offer sheet on the table.
Nunn isn't the only notable free agent the Heat have to worry about, either, with Goran Dragic, Andre Iguodala and Duncan Robinson all hitting the open market. Like Nunn, Robinson is an RFA, thus presenting the same issue addressed above.
Because his price tag shouldn't be exorbitant, you'd expect Nunn to return to Miami. However, he isn't so good as to be irreplaceable if the front office decides to devote its resources elsewhere.