Ballplayers not being baseball cards, we shouldn’t be cavalier about recommending that a player’s team discuss him in trade talks.

It’s due to Mason Miller’s excellence that I’m recommending the Padres be open to fielding offers on their uber-closer and lone All-Star, whose fight against juvenile diabetes has made him a role model to numerous San Diegans and many others in the country.

As baseball’s best relief ace, Miller is almost untouchable on the mound.

That doesn’t mean the Padres should deem him untouchable in the trade market ahead of the Aug. 3 deadline.

Let other teams make that determination.

If no one meets the high price for a door-slammer who took MLB’s best strikeout rate and an ERA of 0.78 into Saturday’s game at Dodger Stadium, the Padres will have lost nothing.

They may have gained valuable intel that only blue-chip trade candidates can extract, and they’d still have Miller, who’s under contract through 2029.

If Miller were baseball’s best player at most other positions at age 27, the calculus would likely be different.

Relievers’ careers tend to produce more volatility, and the Padres do nothing better than find effective closers. Building on that franchise legacy, A.J. Preller struck gold with inexpensive additions such as Kirby Yates, Robert Suarez, Mark Melancon, Brad Hand and Fernando Rodney.

Josh Hader is another one. He was well worth the price of the two minor leaguers Preller dealt to get him from the Brewers four summers ago. One of the great what-ifs of Padres history involves Hader: what if Bob Melvin had brought in a peak-form Hader to face fellow lefty Bryce Harper in the NLCS Game 5 against the Phillies?

Miller is pitching at a higher level than Hader and the others.

A 6-foot-5 right-hander with a triple-digit fastball and a wipeout slider, he has averaged more than 17 strikeouts per nine innings since joining the Padres last August in a trade-deadline move that sent Double-A shortstop and top prospect Leo De Vries to the A’s. In October, Miller struck out eight of the nine Cubs he faced in his first taste of the postseason.

Fielding independent ERA (FIP) strips out the influence of fielders and luck on balls on play.

Miller’s majors-best FIP of 0.43 is less than half of MLB’s next one — the 1.12 mark logged by Phillies All-Star Jhoan Duran.

Entering Saturday, Miller hadn’t allowed a home run this year in his 34.2 innings. An All-Star with the A’s, too, he shows a 2.10 FIP and 2.45 career ERA accrued in 158 games and nearly 200 innings

Preller hasn’t gone into an aggressive selloff in any of the past six summer trade markets, and his current team still has an opportunity to motivate him to become a buyer rather than a seller. The Padres went into Saturday four games behind St. Louis in a crowded race for the third and final playoff spot.

Asked if the trade market’s possibilities could become a distraction for Padres players, manager Craig Stammen noted that “we’re far away” from the Aug. 3 deadline.

“I don’t think they’re thinking about it yet,” he said. “When it gets closer, obviously all the reports come out of different names being thrown out, my only thing for them is 99% of it, all the stuff that’s written is not true, you know, and most of the things that do happen are things that nobody knows about, or they’re pretty obvious. So, you know, in the end we gotta go out and compete every single day, and the more we get focused on that, the better off we’ll be.”

Miller said that he’s aware of how baseball works this time of year. “It’s the business of baseball,” he said.

The chance of Miller attracting a very hard-to-refuse offer would rise if more baseball GMs were wired like Preller.

In this six-year Padres era, at least, Preller has tended to value present value more than future value in parting with prospects who were well-regarded by the industry, such as James Wood, CJ Abrams and DeVries, to fortify World Series bids of Padres teams.

The shortstop De Vries, now 19, was the highest-ranked prospect, as judged by media analysts, who was moved in last year’s trade market. While Miller’s improvement from very good with the A’s to best-in-class with the Padres may increase his trade value this time around, the trading club would have one year less of contractual control than the Padres obtained.