Paul Pierce already knows which number Boston will retire next.

The Celtics great is confident that Kevin Garnett's No. 5 will soon hang beside his No. 34 in the rafters at TD Garden.

"Without a doubt, KG's number will be [the next one] retired in Boston," Pierce said, via ESPN. "It's going to happen.

"[Garnett would] rather have his jersey retired in Boston than in Minnesota. He'll eventually have his number retired with the Timberwolves, too, but he'll have to wait until management sells the team."

Pierce, 40, played his first 15 seasons with the Celtics and signed a one-day contract with the team last summer so he could retire as a member of the franchise. He was honored during a pregame ceremony ahead of the team's loss to the Cavaliers on Sunday.

While Garnett played six seasons with the Celtics after being acquired from the Timberwolves, some believe his tenure in Boston wasn't long enough to warrant his number being retired. Still, Celtics president of basketball operations Danny Ainge believes Garnett deserves to be commemorated.

"It was six years of potential championship-caliber teams and All-Star play from KG," Ainge said. "I think that it was a pretty significant impact he had in those six years."

Garnett, 41, announced his retirement from basketball in September 2016 following a notable career than spanned 21 seasons and garnered 15 All-Star selections in addition to NBA MVP honors in 2004.