Editor’s note: The Chronicle is reviewing the season of each player after the Warriors’ second straight championship run.

Kevon Looney’s emergence as a reliable rotation player was one of the more surprising developments in a Warriors season loaded with story lines.

Last July, Looney’s career was seemingly on life support. Now, after playing a key role in Golden State’s championship run, he figures to be a sought-after free agent.

At 22 with an ability to guard all five positions, Looney is the type of young, small-ball center prized in the modern NBA. But it is his diligence, not any physical tool, that has most endeared him to head coach Steve Kerr.

Last summer, after a second injury-marred season, Looney was desperate for something — anything — to help him resuscitate his career. After talking with teammates and coaches, he decided that defensive versatility would be his trademark.

Finally healthy, Looney went on a variation of the Paleo diet and shed 30 pounds from his 6-foot-9 frame. In open runs at UCLA, after games of 5-on-5, Looney often enlisted three guards for some 2-on-2. During those sessions, he came to understand the angles and spacing necessary to stick in front of much smaller, quicker players.

Still buried on the depth chart in late October, Looney didn’t have his fourth-year option picked up by Golden State. It wasn’t until Jordan Bell sprained his ankle in mid-January that Looney finally began to carve out a rotation spot.

After averaging 2.5 points and 2.5 rebounds in 9.8 minutes per game in February, he averaged 6.6 points, 4.5 rebounds, 1.5 blocks and 1.2 steals in 21.1 minutes in March. Kerr began starting him against small, up-tempo lineups. After playing solid defense on Houston’s Chris Paul and James Harden in the Western Conference finals, Looney was a factor in the Warriors’ NBA Finals sweep of Cleveland, chipping in eight points and four rebounds in Game 1.

As other teams prepare to try and lure him away from Golden State, Looney has made one thing clear: He will be a rotation player, whether that is with the Warriors or elsewhere.

Offseason outlook: It isn’t a matter of whether the Warriors want to re-sign Looney, but whether the team can afford him. The problem for Golden State is that, because it declined his fourth-year option, it can offer him only $2.2 million.

Per ESPN’s front-office insider, Bobby Marks, Looney should command in the neighborhood of $3 million to $4 million in unrestricted free agency. It is unclear how willing Looney would be to turn down bigger offers for more championship runs with the Warriors.

Connor Letourneau is a San Francisco Chronicle staff writer. Email: cletourneau@sfchronicle.com Twitter: @Con_Chron

More Information Kevon Looney bio Age: 22 Position: Small forward Ht./Wt.: 6-9, 220 pounds Hometown: Milwaukee College: UCLA Years pro: 3 2017-18 averages: 4.0 points, 3.3 rebounds, 13.8 minutes per game Contract status: Looney will become an unrestricted free agent on July 1. Boucher to be waived The Warriors are waiving forward Chris Boucher, a source has confirmed with The Chronicle. One of two Golden State players on a two-way contract last season, he averaged 11.8 points, 7.5 rebounds and 2.1 blocks in 22.2 minutes per game with the G-League affiliate Santa Cruz Warriors. In mid-March, Boucher made a one-minute NBA cameo during the Warriors’ win over the Lakers. Boucher, 25, will be an unrestricted free agent once he is waived by the Warriors. — Connor Letourneau