Marion, 36, has career averages of 15.4 points, 8.8 rebounds, 1.9 assists, 1.5 steals and 1.1 blocks per game while building a defensive reputation as someone able to guard all five positions on the court.
"I wanted to go out on my terms," Marion told the Arizona Republic in a story published Wednesday afternoon, adding that being away from his first child, 8-month-old son Shawn, is driving the decision.
He spent his first eight and a half seasons in Phoenix after being drafted by the Suns out of UNLV with the No. 9 pick in 1999. Marion then bounced around with short stints in Miami and Toronto before spending five seasons in Dallas, winning a title with the Mavericks in 2011.
The 6-foot-7 forward was a four-time All-Star and named to the All-NBA 3rd Team twice in his career.
"He's a 16-year veteran," Cavs coach David Blatt said Wednesday. "When Shawn Marion decides to retire, that will not be a negative in any way. He's a great professional. He's played at a high level for 16 years. He's a great guy. Whenever that day comes, he'll have to be in the discussion for the Hall of Fame."
Marion told the Northeast Ohio Media Group that he is deserving of a spot in Springfield, Mass.
"I'm not in control of that but I think my numbers speak for themselves," Marion said. "What I've done on this court in the last 16 years at my position, I don't think nobody has ever done it the way I've done it."
Marion has started 22 of the 39 games he's played this season for Cleveland, but is averaging career lows in points (5.6), rebounds (4.0), assists (1.1) per game as well as shooting a career-worst 42.3 percent from the field coming into Wednesday.
Despite the dip in production, the man known as "Matrix" is still making an impact.
"As far as a locker room guy goes and always being kind of a free spirit and having a great person around, he's been one of the best teammates that I've ever had," Kevin Love said. "I love being around 'Trix. I think each and every person would agree he's had a great career and hopefully we can end it in the right way, not only for him but for everybody on this team. Obviously I mean this year, because it's his last one."
Marion had six points on 3-for-3 shooting with a steal and a rebound in 16 minutes Wednesday, helping the Cavs to their fourth win in a row with a 106-92 romp over Utah, but left without speaking to reporters.
"I think that Shawn coming in here, he probably played even more minutes than he expected or we expected due to the circumstances," Blatt said earlier this week. "He's really made the effort to give us the things that he's always given which is great gray-area play, great multiple-position play. Shawn is a very special NBA player.
"There's not a lot of guys like Shawn Marion. You look at his body of work and the things that he's actually accomplished without having a real particular kind of skill set. It's really amazing what Shawn has accomplished in his career and how effective and how efficient and how great a basketball player he's been for 16 years in this league. Shawn is a guy that gives you so much without a particular definition and that's what makes him special."