Colston, 32, has had a remarkable 10-year career since being drafted in the seventh round out of Hofstra in 2006, compiling 9,759 yards and 72 touchdowns as well as a Super Bowl ring. But he became New Orleans' No. 3 receiving option last year while missing three games with injuries, and he is due to earn $3.2 million in salary and bonuses this year.
The move isn't strictly motivated by the salary cap, since the Saints are already a few million dollars under the projected 2016 cap. However, they do rank among the teams with the least cap space, which puts a premium on every dollar they spend.
Colston will count for $2.7 million in dead money on the Saints' salary cap from past signing bonuses.
The Saints also released another one of their all-time greats earlier this month: guard Jahri Evans, who was a member of that same 2006 draft class.
It's unclear if Colston will consider retirement or if he will try to pass the 10,000-yard threshold with another team.
Nicknamed "the Quiet Storm" for his quiet demeanor, Colston has been an instrumental part of the Saints' record-breaking passing offense under coach Sean Payton and Brees. The 6-foot-4, 225-pounder caught the first TD pass Brees ever threw with the Saints in Week 1 of that 2006 season and went on to rack up six 1,000-yard seasons in his first seven years -- though he never made a Pro Bowl.
Colston held the NFL record for most receptions in the first two seasons of a career with 168 until last year, when former LSU teammates Jarvis Landry and Odell Beckham Jr. both passed him. Brees and Colston rank fifth in NFL history with 72 TDs as a duo.
"He's one of the most unselfish players I've ever played with, one of the greatest teammates I've ever had, one of the most dependable, most reliable people I've ever played with," Brees said late last season."I consider myself lucky to have had, so far, these 10 years with him. And he never ceases to amaze me, just some of the big plays he has the ability to make."
"Shoot, he has epitomized just consistency," Payton said late last season. "He's epitomized what you look for in a pro player, especially with the time he's done it."
Nevertheless, Colston's expected release does not come as a surprise due to his age, his salary and his diminishing role. Colston's 45 receptions, 520 yards and four touchdowns were all career lows.
He missed one game with a shoulder injury early in the year, then he missed the final two games with a chest injury. Although Colston remained a dependable target over the middle of the field in clutch situations, he was passed up in the pecking order by second-year receivers Brandin Cooks and Willie Snead and veteran tight end Benjamin Watson.
Recently, Saints general manager Mickey Loomis also talked up the potential of third-year receiver and fellow big man Brandon Coleman (6-6, 225) in an interview with SiriusXM Radio as a possible "heir apparent" to Colston.
Colston's release was also a possibility in 2015 before he agreed to a significant pay cut to stay in New Orleans. At the time, he said some factors were more important than "maximizing every penny out of every contract."
"I look at things just from a business standpoint. You look at the position I play, I'm kind of dependent on everyone else along the offense to have success," Colston said last offseason. "And just being a football fan, I've seen guys at my position chase every penny and not really have the career or the success that they've been accustomed to. So I always say I'm never gonna be in a hurry to leave a Hall of Fame quarterback."