By Chris Melore
CBSNewYork.com

Brian Cashman has been the Yankees’ general manager since 1998. He’s lasted longer and overseen more success than any of his peers in Major League Baseball.

But Cashman’s decisions in 2018 may shape his reputation among fans for years to come.

The 51-year-old executive has spent the last three seasons re-molding the Yankees into a younger and more analytically-driven franchise. His moves have cleared payroll, enriched the farm system, and turned New York back into a regular postseason threat.

MORE: Yankees, Red Sox Ready To Rumble Again In Playoffs

Despite being at the head of the Yankee front office for two decades, Cashman’s control over every aspect of the team seems more apparent this year than any other and begs the question: Is his reputation for baseball brilliance at risk if the Yankees fail in October?

BRIAN’S MIDDLE-MAN OR MANAGER?

Aaron Boone’s selection to replace Joe Girardi as manager was widely seen as Cashman’s move to place an extension of the front office in the dugout. The head-scratching number of different lineups New York rolled out — a staggering 138 in 162 games — led many to believe Cashman’s analytics staff had more control over the daily batting order than the team’s rookie skipper.

gettyimages boone Cashmans Many Decisions Will Be Put To The Test In Showdown With Red Sox

Yankees manager Aaron Boone (Photo by Julio Aguilar/Getty Images)

A replay blunder by Girardi in 2017’s ALDS nearly cost the Yankees the series against Cleveland. Boone will likely face the same amount of scrutiny if things go badly against Boston, but even after a full season in the Bronx, it’s still unclear how much say Boone has over the day-to-day decisions.

PASSING ON AN ACE AGAIN

The Yankees’ general manager has been a savvy trader over the years, but his choice to pass on several big-name starting pitchers has already proven costly.

Cashman’s decision to trade for the cost-effective Sonny Gray instead of Justin Verlander — and thereby absorbing his big salary — may have singlehandedly cost New York a trip to the World Series last year. Verlander dominated the Yankees twice in the AL Championship Series while Houston only had to pick up $20 million of the $28 million owed to the ace this year.

Although the Yankees were reportedly in play for big arms like Jacob deGrom, Noah Syndergaard, Gerrit Cole, and Cole Hamels over the last year, New York failed to pull the trigger on a blockbuster trade. Cashman settled on J.A. Happ, who will now take the ball in Game 1 against the archrival Red Sox on Friday night.

Happ, who could possibly pitch twice if the series goes five games, may decide the fate of the Yankees’ season for better or worse.

BIG PICKUPS WILL PLAY CRITICAL ROLES

Due to injuries and inconsistent play, the Yankees’ roster heading into Boston looks a lot different than the one that left spring training in March. Cashman has struck gold more than once, but his acquisitions are about to face the biggest tests of their careers.

New York chose to double-down on offense by trading for NL MVP Giancarlo Stanton. Despite 38 home runs and 100 RBIs, Stanton was streaky at best and struck out a franchise-record 211 times. The team’s designated hitter homered in his first playoff game Wednesday and the Yankees will need him to avoid a cold streak to take down Boston.

gettyimages voit Cashmans Many Decisions Will Be Put To The Test In Showdown With Red Sox

Yankees first baseman Luke Voit celebrates after scoring a run against the Oakland Athletics during the sixth inning iof the AL wild-card at Yankee Stadium on Oct. 3, 2018. (Photo by Elsa/Getty Images)

Cashman’s greatest roster move of 2018 was swapping Chasen Shreve and a minor leaguer for Luke Voit. The 27-year-old has stunned the baseball world by smashing 14 homers in just 39 games. The emergence of Voit has also helped Cashman sort of sweep under the rug the failings of Greg Bird, who the organization finally had to bench despite enormous support from management.

Cashman also traded for stars Zach Britton and Andrew McCutchen, who will play pivotal roles in the Division Series out of the bullpen and in left field, respectively.

THE FUTURE IS NOW

While Cashman has assembled the youngest Yankees team since the early 1990s, it will be hard for fans to “wait ’til next year” after a 100-win season and an MLB-record 267 home runs.

For the team’s general manager, even more could be at stake. Beating the Red Sox and getting back to the ALCS with his handcrafted roster could cement his legacy as the franchise’s greatest front office executive.

A loss could bring questions that Cashman has his hands on too many aspects of the team.

Read more columns by Chris Melore