Mariners' $100M extension for Kyle Seager is savvy move for Seattle

The underrated Kyle Seager got a big payday from the Mariners, who wisely locked up their star third baseman with a seven-year, $100 million extension.

The Mariners are on the verge of signing All-Star third baseman Kyle Seager to a seven-year extension worth $100 million with a club option for 2022, according to Yahoo! Sports' Jeff Passan. The contract would take Seager, who turned 27 earlier this month, through his age-33 season, with the option covering his age-34 campaign. It's a particularly astute move by a Mariners front office that has executed few such transactions.

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​Seager is one of several young third baseman who have emerged as stars in the last few years, a group that also includes the Athletics' Josh Donaldson, the Cardinals' Matt Carpenter, the Reds' Todd Frazier, the Orioles' Manny Machado, the Rockies' Nolan Arenado, the Nationals' Anthony Rendon, and the Pirates' Josh Harrison, none of whom were arbitration eligible prior to this offseason. Of that group, Seager is the most experienced at the major league level but is in the middle of the pack in terms of age, older than Machado, Arenado and Rendon but younger than Donaldson, Carpenter, Frazier, and Harrison. Also, his 2014 season was the third most valuable by a member of that group according to Baseball-Reference's Wins Above Replacement, with his 5.8 bWAR ranking behind only the defense-dependent showings of Donaldson (7.4) and Rendon (6.5).

Seager, who was arbitration eligible for the first time this offseason along with Donaldson, Frazier and Harrison, is just the second member of that group to sign an extension. The Cardinals locked up Carpenter, who was also due to be arbitration eligible for the first time this offseason, with a six-year, $52 million deal in March, thus including one pre-arbitration season among those six years. Carpenter's deal looks even better now than when it was signed, given the way the market has expanded. Seager's deal is significantly more expensive, but it buys out two more of his free-agency years relative to Carpenter's pact and includes no pre-arbitration seasons. It is also a contract that will set the market for the other players on that list, rather than one that has to follow a market set by others.

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A third-round pick out of the University of North Carolina in 2009, Seager made his major league debut in July 2011 and emerged as the Mariners' everyday third baseman in 2012, quickly establishing himself as a valuable but perhaps still-underrated player. Seager's .259/.316/.423 line in 2012 wasn't terribly impressive on its face, but after correcting for pitcher-friendly Safeco Field, it translated to a 108 OPS+ for a 24-year-old in his first full season in the majors and came with a more easily appreciated 20 home runs and 86 RBI.

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​Seager has only improved from there, defying the league-wide drop in offense by improving his on-base percentage in 2013 and adding power in 2014. The result was a .268/.334/.454 line with 25 home runs and 96 RBI, a 127 OPS+, and his first All-Star berth this past season. Seager also took a big step forward in the field this past year. According to all of the major advance fielding statistics, as well as casual observation, Seager was legitimately excellent, earning him his first Gold Glove (one that should have gone to Donaldson, but that doesn't diminish Seager's accomplishment).

According to bWAR, Seager's 2014 season was the third most valuable by a Mariners third baseman in team history, behind only Edgar Martinez's 1991 and '92 seasons. By that measure, it was also the third most valuable by a Mariners hitter at any position since Ichiro Suzuki set the single-season hits record in 2004. The only Mariners hitters to surpass Seager's 2014 in bWAR since then have been Franklin Gutierrez in 2009 for a 6.6 bWAR season in which his glove was more valuable than his bat, and Robinson Cano in his Mariners debut this past year (6.4 bWAR).

Cano, who just turned 32, is owed $216 million over the next nine years at $24 million a year. Seager, who is five years younger, is now under team control for seven of those nine years at an average of just $14.3 million per year. Seager's track record may not be as long as Cano's, and his peak is unlikely to be as brilliant, but it's difficult not to see Seager's new extension as a team-friendly deal, even if you dismiss Cano's contract as a dramatic overpay.

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​Seager's extension comes in the immediate wake of the news that the Red Sox have signed Pablo Sandoval to a five-year deal worth "close to" $100 million. Sandoval is only a year older than Seager, but his numbers at the plate are trending in the opposite direction. Meanwhile, the Mariners are getting four of Seager's free-agent years and all three of his arbitration years for roughly what the Red Sox are paying for five free-agent years of Sandoval, a player who may be as overrated as Seager is underrated.

Seager joins the Marlins' Giancarlo Stanton, who was in his second year of arbitration eligibility, as players to sign significant extensions this offseason. Other players reaching arbitration for the first time this winter, in addition to Donaldson, Frazier and Harrison, include Lorenzo Cain, Kelvin Herrera, Lance Lynn, Alex Cobb, Garrett Richards, Chris Tillman, Devin Mesoraco, Dee Gordon, Brandon Crawford, Astros slugger Chris Carter, and the Nationals' Wilson Ramos and Drew Storen. The Nationals are also facing the possibility of Jordan Zimmermann, Doug Fister, Ian Desmond, Denard Span, and Tyler Clippard all entering their walk years in 2015.

Expect several of those players to join Seager in signing long-term extensions this winter, once again making it to the Mariners' credit that they got this deal done ahead of the market.