Giants’ big decision: Should they trade Madison Bumgarner?

Dealing World Series legend could be a defining moment

This is the ninth inning for Madison Bumgarner, who likes to finish the job. The ball is his until further notice.

Except this time, it can be stripped from his grasp even if he’s pitching his best and helping the Giants win.

Such are the cruelties and realities of baseball’s trade deadline. The Giants might be on the verge of orchestrating one of the biggest trades in franchise history, involving their greatest World Series pitcher since the legendary Christy Mathewson.

If the trigger is pulled on Bumgarner before the July 31 deadline, not only would he undergo an extreme career change, but it would be a defining moment for Farhan Zaidi, who was asked to turn around the Giants’ fortunes as the firstyear president of baseball operations. Bumgarner’s contract expires after this season, making him a free agent, and it would be no surprise if he’s moved because players the Giants receive in a trade could benefit them in the long term.

While the Giants have one eye on a rebuild for the future, they’ve got the other on the playoff race, which they’ve suddenly and unexpectedly joined.

This makes the days leading to the trade deadline more interesting yet more complex. The same fans who want a promising future also wouldn’t mind if this year’s team keeps flirting with a run toward October.

Zaidi must weigh the importance of each when it comes to making his final decisions, especially with Bumgarner, who turns 30 the day after the deadline and remains one of the most popular Giants of all time.

A significant reason the Giants won championships in 2010, 2012 and 2014, Bumgarner this season is 57 with a 3.65 ERA, not exactly a reminder of his glory days.

On the other hand, he’s averaging more than one strikeout per inning for the first time since 2016, his last AllStar season, and his average fastball velocity of 92.1 is his highest in four years. His ERA in his past five starts is 1.55.

Perhaps Bumgarner’s greatest appeal is his postseason track record. He threw shutouts in each of his wildcard starts and has a 2.11 ERA in 1021⁄3 innings, including a 0.25 ERA in 36 World Series innings. Mathewson’s World Series ERA in the early 1900s was 0.97.

No wonder Bumgarner is the top starting pitcher on the market and potentially a perfect fit on several playoffbound teams.

Imagine Bumgarner joining Justin Verlander and Gerrit Cole in Houston’s rotation. Or suiting up in Yankee pinstripes alongside starters Masahiro Tanaka, James Paxton, Domingo German and CC Sabathia.

Or inspiring a young Braves team. Or leading the Twins or Brewers, both of whom could ride Bumgarner to the next level.

Before the offensively challenged Giants turned into a runscoring juggernaut in recent weeks, the biggest void was powerhitting outfielders. Zaidi tried a laundry list of candidates before settling on Alex Dickerson in left and Mike Yastrzemski in right, flanking Kevin Pillar. None appeared on the Opening Day roster, but all have made contributions to the recent surge. It’s too soon to suggest either corner outfielder is a longterm answer, so acquiring young hitters still would be a priority.

Zaidi has given opportunities to many players — those he brought in as well as those he inherited — and called his rosterbuilding a work in progress, which hasn’t necessarily sat well with fans. At the same time, he had hoped to find the right guys to be competitive this year knowing it would make his decisions more difficult at the deadline. Here we are.

There’s still time to evaluate before deciding which way to go. If the Giants keep winning, the chances of holding on to Bumgarner could escalate. As the rotation anchor, he could help orchestrate a playoff run in manager Bruce Bochy’s final season.

Plus, many fans would dig seeing the lefty play out his contract in San Francisco, in which case the Giants could give him a qualifying offer after the season and gain a compensatory draft pick after the first round if he signs elsewhere.

Bumgarner’s contract includes a notrade clause to

eight teams, and he picked expected contenders (Astros, Braves, Brewers, Cardinals, Cubs, Phillies, Red Sox, Yankees), a strategic move that gives him leverage should one of those teams ask him to withhold his veto.

It must be noted that a trade would benefit Bumgarner in free agency because he’d be ineligible for a qualifying offer, thus creating interest from more teams, including those willing to sign free agents but unwilling to forfeit draft picks as a result.

Zaidi also has several relievers he can deal — starting with closer Will Smith and setup man Sam Dyson — and they might bring in a hefty haul considering how many contenders need relievers. Dyson and fellow righthander Reyes Moronta, who are under team control through next season, might be especially attractive.

Zaidi has stated he has promising pitchers in the minors who could step in.

In that sense, it’s possible Zaidi could be all encompassing at the deadline. He could trade assets not only with the future in mind but to keep the 2019 team competitive, making targeted deals to add players in key spots that might be an upgrade. The next Dickerson or Pillar, for example.

Either way, Zaidi won’t part with his elite prospects.

Parting with Bumgarner is another matter. Three years after the Giants’ last playoff appearance and five years after their last World Series, it no longer would be shocking if he’s dealt. In fact, when asked about trading Bumgarner at his introductory news conference in November, Zaidi helped soften this moment by saying “everything’s got to be on the table.”

For Bumgarner, the Giants probably could get at least one top prospect to match the draft pick they’d receive if they were to give him a qualifying offer.

Ownership has given Zaidi free rein to renovate the roster and likely wouldn’t balk at a Bumgarner trade with significant time passed since the Giants’ glory years.

There’s also the possibility the Giants would trade Bumgarner and resign him after the season, though that seems a stretch. For now, Bumgarner is in the ninth inning and wondering if he’ll complete the job with the Giants.

He seems determined to do so. He may not get the choice.

John Shea is The San Francisco Chronicle’s national baseball writer. Email: jshea@sfchronicle .com Twitter: @JohnSheaHey

Scott Strazzante / The Chronicle Madison Bumgarner, who is about to become a free agent, could be traded for prospects.

Photos by Scott Strazzante / The Chronicle Madison Bumgarner returns to the dugout after retiring the Mets on Thursday in perhaps his last appearance for the team.

If another team trades for Bumgarner, they’ll get a redhot pitcher. The velocity on his fastball is the highest it’s been in four years and his ERA is 1.55 in his past five starts.

Bumgarner can block some of his potential new employers. His contract includes a notrade clause to eight teams, including many contenders who might be interested in him. On the list: the Astros, Braves, Brewers, Cardinals, Cubs, Phillies, Red Sox and Yankees. The clause could give him leverage if a team asks him to waive the notrade clause.