SEATTLE -- Friday marked one of the final significant dates on MLB’s offseason calendar, the deadline for salary arbitration-eligible players to exchange figures with their clubs. The Mariners had six cases: Tom Murphy, Ty France, Teoscar Hernández, Dylan Moore, Diego Castillo and Paul Sewald.

France ($4.1 million), Sewald ($4.1 million) and Murphy ($1.625 million) agreed to terms, while the other three are still outstanding. However, each are under club control and should agree to terms before the season.

Here’s a primer on the day:

What is salary arbitration? 
Players with three or more years of MLB service time but fewer than six (when they qualify for free agency) can negotiate their salaries for the upcoming season, which are primarily based on comparable players who have signed contracts in recent seasons. The player and the club will each present a salary figure no later than Friday at 10 a.m. PT.

If the player and club cannot agree to terms, then a hearing is scheduled in February, when a panel of arbitrators, who, after hearing arguments from both sides, selects either the salary figure of the player or the club.

Players and clubs can continue to negotiate salaries between Friday and a potential hearing on a one- or multiyear deal, which is typically how these negotiations settle.

What’s the situation for each arbitration-eligible Mariner? (All projections via Cot’s Baseball Contracts)

• C Tom Murphy (third year, $1.625 million): He was off to a stellar start, slashing .303/.439/.455 (.894 OPS) in 14 games before suffering a season-ending left shoulder injury. As such, he received only a marginal raise from the $1.575 million he earned in 2022.

• 1B Ty France (first year, $4.1 million): An All-Star for the first time -- and for most of the year, Seattle’s most consistent hitter -- France received a big raise from the near league minimum $734,500 he netted last season. He’s under club control through 2025 and will earn far more in the next two years if he stays on this trajectory.

• OF Teoscar Hernández (third year, $15 million projected): Seattle’s biggest acquisition this offseason is slated for an increase from the $10.65 million he earned last year, when he crushed 25 homers in Toronto and was worth 2.4 wins above replacement, per FanGraphs. He’ll likely become the second-highest paid Mariner in 2023 behind Robbie Ray ($21 million), per Cot’s, as Luis Castillo and Julio Rodríguez’s contract extensions don’t become more expensive until later.

• UTIL Dylan Moore (second year, $2.25 million projected): Moore is slated for a pay raise from the $1.35 million he earned after another productive year as the club’s utility man. He was worth 2.1 WAR and produced a 122 wRC+ (league average is 100).

• RHP Diego Castillo (second year, $3.5 million projected): Castillo had another solid season with a 3.64 ERA, 102 ERA+ and 53 strikeouts in 54 1/3 innings. And given that he’s in his second year of eligibility, he’s in line to earn a raise from the $2.15 million he netted last year.

• RHP Paul Sewald (second year, $4.1 million): For the second straight year, Sewald was one of the AL’s best leverage arms despite his strikeout numbers taking a dip (from a 39.4% rate to 29.8%). It’s a big payday for a player who nearly called it quits before resurrecting himself in Seattle.

How often do cases reach arbitration? 
It hasn't happened since general manager Jerry Dipoto took over after the 2015 season. And only twice since 2000 has Seattle gone all the way to a hearing -- in '15, when reliever Tom Wilhelmsen lost his case requesting $2.2 million and the panel choosing the team’s $1.4 million offer; and in ’03, when starting pitcher Freddy Garcia won his case for $6.875 million over the team's $5.9 million offer. The Mariners have had 20 cases go to a hearing in the franchise’s 43-year history, but 17 of those were from 1980-93.

How will arbitration negotiations affect the rest of the Mariners’ offseason? 
It shouldn’t at all. Even if they go to court, arbitration situations give clubs ample payroll clarity in advance because those players are forecasted to earn a set figure based on performance and service time. The better and more experienced the player, the higher the salary. That said, the Mariners were already operating with a roughly $137 million Opening Day payroll, per Cot's, when forecasting the likely earnings of their arbitration players.