How do you let Tom Seaver go? A rhetorical question for most, but the Mets actually had an answer on June 15, 1977 when they traded him to the Reds. Five-and-a-half seasons later, Seaver came back to Queens. In 1983, his 17th big league season, he made 34 starts, posted a respectable 3.55 ERA, and had the third-best bWAR (2.6) for a young team that managed just 68 victories.

At age 39 and on the verge of win No. 300, it made all the sense to envision Seaver finishing his career where it started.

That said, how do you let Tom Seaver go…twice?! Leave it to the Mets to create an unforced error.

A recently implemented rule stated that each club was required to protect 26 players from claims in a free-agent compensation pool. For the Mets, their list did not include Seaver.They felt no team would claim a pitcher in his twilight, only to be stunned when the White Sox did.

The situation dumbfounded almost everyone — Seaver included.

“The Mets certainly made a mistake by not protecting me,” he said during a press conference held at Shea Stadium. ”You don’t have to be a Harvard law student to figure that out.”

Majority owner Nelson Doubleday and President Fred Wilpon were “devastated” by it. Frank Cashen, the general manager in the process of building a perennial contender, took the blame.

”Mea culpa, mea culpa, mea maxima culpa,” he said. “I had the final decision, I made a mistake. We made a calculated and regrettable gamble.”

By allowing “The Franchise” to land with another franchise, it prevented fans from witnessing a linkage of pitching generations with “Tom Terrific” and incoming rookie “Dr. K” in the same rotation. Gone was the opportunity for Seaver to get the coveted 300th victory in a Mets uniform. And the chance for the team’s eternal icon to be a part of their latest resurgence was missed — a revival that kicked in by 1984 and with the 1986 World Series triumph over Boston, the club Seaver played for in his final year.

Seaver went on to pitch two-plus seasons on the South Side of Chicago, totaling 38 victories and an ERA+ of 116. He was still able to reach the 300th victory milestone in New York. Only that it happened to be at Yankee Stadium while sporting that hideous White Sox road jersey.

Tom Seaver and the Mets will forever be synonymous. But he should’ve been a Met for life — or, at least, a Met ’til the end.