Trade deadline and deadline-adjacent notes on Mets’ Luis Severino, Pete Alonso, Edwin Diaz, J.D. Martinez and more

The consensus among rival executives and evaluators is that the Mets’ most valuable trade chip, by far, is their starting pitcher on Thursday, Luis Severino.

“Severino gets you an average prospect,” said one high-ranking American League executive.

The case of star first baseman Pete Alonso, however, is more complex.

The Mets have not yet decided to become trade deadline sellers. In fact, as we’ve previously reported, they would strongly prefer to avoid that approach for a second consecutive season. But if closer Edwin Diaz does not return to form, it’s hard to see a path to contention.

While the Mets hope that Diaz, activated from the injured list on Thursday, can recover his confidence — and manager Carlos Mendoza sees signs that he will — rival evaluators remain concerned that he is not fully healthy.

Diaz missed all of last season after injuring his knee in the World Baseball Classic. Pitching with reduced velocity and command, he has a 5.40 ERA and has blown four saves in nine chances. He went on the injured list on May 29 with a right shoulder impingement.

One evaluator posited that Diaz this year was “all arm, like he’s trying to protect the knee.”

Diaz says that he is healthy.

In a recent conversation with Diaz, Mendoza felt that the Mets closer came across as far more confident than when he was in the middle of his May slump. With few, if any, better options, Mendoza will immediately restore Diaz to the closer role.

If Diaz succeeds, it is easier to imagine the Mets hanging around the Wild Card race. If he does not, they could determine, albeit reluctantly, that selling is more prudent.

Of the players on expiring contracts who the Mets could sell, Severino stands out in his appeal to other teams.

Others, like Harrison Bader, Adam Ottavino and J.D. Martinez are expected to fetch only modest returns.

Alonso’s case divides baseball folks. Many note that the rental market for right-handed sluggers is not usually robust, hence the expectation of a smaller return for Martinez.

“For a rental, you don’t get much of anything for Alonso unless there is a bidding war,” said one evaluator.

Said another veteran executive, “Alonso maybe gets you someone’s 5-10 rated prospect. Not someone who is a stud.”

“I don’t agree with that,” a high-ranking A.L. executive said. “Pete could be the difference between making the playoffs or not. He is better than Arraez [Luis Arraez, for whom Miami acquired reliever Woo-Suk Go and three prospects from an aggressive Padres team].”

If the first two quotes are correct, it would make more sense for the Mets to hold Alonso until he reaches free agency at the end of the season. Why put a fan base through a traumatic trade just to receive a minor leaguer who might or might not turn into a big leaguer?

But if the third executive is correct, and teams view Alonso as a difference-maker, the Mets will have to consider it. It will be up to president of baseball operations David Stearns and his group to gauge his value and proceed accordingly.