By Cliff Corcoran

Despite the fact that several compelling free agents remain unsigned, the hot stove has largely gone cold over the last few weeks. That flame hasn't flickered out just yet, however, and a new source of fuel will soon stoke the fire as teams open negotiations with their arbitration-eligible stars regarding their salaries for the coming season, and in several cases, potential long-term extensions. With that in mind, here are the five players teams should be most aggressive about signing to extensions.

Note that I've limited this list to arbitration-eligible players. That's no slight against pre-arbitration stars such as Kris Bryant, Mookie Betts, Corey Seager, Carlos Correa, Francisco Lindor and Noah Syndergaard, each of whom has given his team good reason to want to retain him beyond his scheduled free agency. But while there is certainly added negotiating leverage for teams dangling eight- or even nine-figure contracts in front of players still making six-figure salaries, there is also no real sense of urgency. Indeed, extending Bryant, Betts, Seager and Lindor this offseason, after top-three MVP finishes in the first three cases and a World Series appearance in the last, might be buying high, while the Mets would be wise to wait on Syndergaard given concerns about the health of his elbow. By default, that would make Correa the top extension candidate of that bunch, but as the list below suggests, the Astros have a more pressing concern elsewhere on their roster.

5. Madison Bumgarner, LHP, Giants

Yes, the Giants have Bumgarner under team control through 2019 via a pair of team-friendly club options. However, the free agent signings of Johnny Cueto, Jeff Samardzija and Mark Melancon have made Bumgarner, the inarguable ace of the staff and an eight-year veteran with three World Series rings to his credit, the fifth-highest-paid pitcher on the team heading into 2017. The Giants got burned on the Matt Cain extension (he's the other Giants pitcher who will make more than Bumgarner this year), but those newer contracts prevent the team from using Cain as an excuse to be stingy with Bumgarner. Another potential source of contention from Bumgarner's side is that a single third-place finish in the National League Cy Young Award voting would increase the value of each of his options by $2 million, but he has just missed that payday twice in the last three years with a pair of fourth-place finishes. 

I criticized the Royals for needlessly adding years and dollars to Salvador Perez's contract last March, but that was because of my pessimism about his continued value beyond the three years of control the Royals already had over him. I'm far more optimistic about Bumgarner's future, despite the fact that he is a pitcher who has endured heavy workloads throughout his early 20s. Bumgarner will be just 29 in the final option year of his current deal. The Giants would be wise to move now to extend him beyond that, offering him more money in the next three seasons in exchange for an affordable commitment beyond 2019.

4. Jose Altuve, 2B, Astros

Altuve's contract status is similar to Bumgarner's. Altuve is under control through 2019 via a pair of team-friendly club options. The difference is that Altuve's options are worth roughly half as much as Bumgarner's in terms of salary, and Altuve doesn't have any of the red flags that accompany Bumgarner (heavy workloads, the simple fact of being a pitcher). Perhaps this offseason isn't an ideal time to extend Altuve given that he's coming off a career year, but a similar logic applies. With Altuve due to make just $4.5 million in 2017 and a total of $17 million through '19, his age-29 season, the Astros can offer him more in salary now in exchange for locking him up at a team-friendly rate at least through Correa's scheduled walk year of '21.

3. Nolan Arenado, 3B, Rockies

There's something brewing in Colorado, with the Rockies coming off their best season since 2010 and boasting a roster flush with young talent including sophomores Trevor Story, David Dahl, Jon Gray and Tyler Anderson. Arenado, who won't turn 26 until mid-April, is the centerpiece of that youth movement. One of the best fielders in the game -- he has been the deserving winner of the Gold Glove Award in all four of his Major League seasons -- and a dangerous hitter who has led the NL in home runs and total bases in each of the last two seasons, he finished fifth in the NL MVP voting in '16. He is now arbitration-eligible for the first time and due to reach free agency after his age-28 season in '19. 

2. Jake Arrieta, RHP, Cubs

Arrieta, the 2015 NL Cy Young Award winner, is entering his walk year, but his ranking here has as much to do with the Cubs' lack of starting pitching depth as the quality of Arrieta's performance. Truth be told, Arrieta experienced a significant correction in '16, and he'll turn 31 in March. For a team with more rotation depth, the wiser play would be to give the late-bloomer at least another half season before considering an extension, and perhaps simply to let him walk. However, the Cubs, for all of their young hitting talent, lack viable near-ready rotation prospects. Given the savings and the elongated window for contention provided by youth in their lineup, the Cubs can afford to make a financial commitment to Arrieta, who having salvaged his career and won a World Series in Chicago, may be motivated to stay. It also makes sense for the Cubs to extend him now so as to include Arrieta's final arbitration year (he made $10.7 million in '16) in the deal.

1. Manny Machado, 3B, Orioles

Bryce who? Given Harper's injury history, the Nationals may actually be better off trading their superstar than attempting to sign him to an extension that, in order to motivate his signature, may have to resemble or even exceed the record-setting deal the Marlins gave Giancarlo Stanton after the 2014 season. 

However, there is another 24-year-old stud due to become a free agent after the 2018 season, one who, according to Baseball-Reference's wins above replacement, has been more valuable than Harper in their five Major League seasons, and after a frustrating year from Harper, now looks like a better bet to provide consistent value going forward. That's Machado, an elite defensive third baseman who can also play shortstop and is an impressive young hitter who took a big step forward at the plate in '15, his age-22 season. Per bWAR, Machado has been worth 6.7 wins above replacement or more in three of the last four seasons. Harper, by comparison, has failed to reach 4.0 bWAR in three of his last four seasons. The Nationals are a better team than the Orioles with a better collection of young talent in the Majors and Minors. They could survive and perhaps even thrive without Harper. The Orioles without Machado, however, could take up long-term residence near the bottom of the always-competitive American League East.

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Cliff Corcoran is a Sports on Earth contributor and a regular guest analyst on MLB Network. An editor or contributor to 13 books about baseball, including seven Baseball Prospectus annuals, he spent the last 10 seasons covering baseball for SI.com and has also written for USA Today and SB Nation, among others.