LOS ANGELES • Kobe Bryant has announced that he will call time on one of the greatest careers in National Basketball Association (NBA) history when he retires at the end of the season.

The five-time NBA champion, who ranks third in all-time scoring with 32,670 points, said in a first-person poem on the Players Tribune website that "this season is all I have left to give".

He spent his entire 20-season career with the Lakers, the first NBA player to stay so long with the same club.

But the member of two Olympic gold-medal squads has been nagged by injuries in recent campaigns and has struggled to find his form this season, the Lakers being off to a miserable 2-13 start in the Western Conference.

Bryant, 37, himself ranks bottom of the league for field goal and three-point percentage among qualified players.

"I can't love (basketball) obsessively for much longer," the 17-time All Star said in his poem, an open love letter to his sport entitled "Dear Basketball".

"My heart can take the pounding. My mind can handle the grind but my body knows it's time to say goodbye. And that's OK. I'm ready to let you go."

NBA commissioner David Silver paid tribute to Bryant's contributions to the league.

"Kobe Bryant is one of the greatest players in the history of our game," he said. "Whether competing in the Finals or hoisting jump shots after midnight in an empty gym, Kobe has an unconditional love for the game.

"I join Kobe's millions of fans around the world in congratulating him on an outstanding NBA career and thank him for so many thrilling memories."

Before Sunday's announcement, Miami Heat's Dwyane Wade had spoken with sympathy about Bryant's current struggles.

"It's tough to see one of the absolute greatest competitors go through this," Wade said.

"You can put a team around a guy to help a guy, especially late in his career. They're just not in position right now to do that.

"He's won five championships, so no one feels bad for him from that standpoint. But from a standpoint of seeing one of this era's greatest players go out in a rebuilding process, it's tough."

Lakers coach Byron Scott said he believes Bryant still has something to offer his team.

"I think he still loves this game," Scott said. "He still has a passion for it. He's still a competitive young man."

It's a unique situation for a Lakers team who lost Shaquille O'Neal to Miami and past legend Magic Johnson to his announcement that he had the HIV virus.

"We're all sad," Lakers president Jeanie Buss said. "This era of Lakers basketball has been one of the most fun, exciting, prosperous eras we could imagine. We're in full support of him. But it's still very sad."

Bryant has averaged 25.4 points, 5.3 rebounds, 4.8 assists and 1.5 steals over 1,280 games.

This season, with the Lakers stripped of much of their supporting cast to bolster Bryant, he is averaging 15.7 points, 4.1 rebounds and 3.4 assists a contest.

His final season will earn him good money - he will be paid US$25 million (S$35.3 million), more than any other player in the league. His farewell tour begins today in Philadelphia, his home town.

Bryant ended his poem to basketball without giving a true hint as to what the future might hold for him.

"We both know, no matter what I do next, I'll always be that kid, With the rolled up socks, Garbage can in the corner, five seconds on the clock, Ball in my hands.

"5 ... 4 ... 3 ... 2 ... 1. Love you always, Kobe."

AGENCE FRANCE-PRESSE, THE GUARDIAN