Closers like Ken Giles don't come along all that often.

The Phillies flamethrower has been one of the most effective relief pitchers in the majors since his debut in June 2014. He is also still the youngest closer in the National League, the second-youngest in either league, and has accrued only one full year of major-league service time, meaning he is under team control for the next five seasons.

But the reasons for excitement among Phillies fans regarding Giles, 25, are the same reasons the team should seriously consider trading their presumed closer of the future.

With a weak group of free-agent relievers from which to choose this winter, rival general managers inquired about Giles last week at the Boca Raton Resort and Club, site of this year's GM meetings. As the still-young baseball offseason wears on, the Phillies' new leadership tandem of club president Andy MacPhail and general manager Matt Klentak must weigh Giles' value to their team, still years from contention, against the potential return in a deal.

If a team is willing to include in a package for Giles at least one prospect the Phillies project to be a productive everyday position player or a front-to-middle-of-the-rotation starter, that is a move worth making. Giles is terrific at shutting down the ninth inning but also occupies baseball's most volatile position. Closers have a shelf life. How many years will Giles' window of productivity overlap with the Phillies' putting a contending roster on the field?

Much of that debate hinges on how far away one believes the Phillies are from contending.

Giles, who made a modest $519,000 last season, is an extremely attractive asset who could speed up the Phillies' transition from long-term rebuilders back to perennial contenders. Over the last two seasons, the only relief pitchers with a better ERA than Giles' (1.56) are Wade Davis (0.97), of the recently crowned World Series-champion Kansas City Royals, and the New York Yankees' Dellin Betances (1.45).

Among major-league closers, only the Toronto Blue Jays' Roberto Osuna, 20, is younger than Giles, who does not turn 26 until late next season. Giles is not even arbitration-eligible until after the 2017 season and is not in line to become a free agent until after the 2020 campaign.

Aroldis Chapman of the Cincinnati Reds is the marquee closer remaining on the trade market. The San Diego Padres on Friday traded Craig Kimbrel to the Boston Red Sox for four prospects. Giles' youth and lack of service time could make him an intriguing alternative for a team such as the Houston Astros, who have a strong farm system.

If a team deals for Chapman, it acquires one of the best closers in baseball and the hardest-throwing pitcher in the game. But in Chapman, the acquiring team also gets a player who will command a big payday after the 2016 season, when he is set to reach free agency. (Kimbrel, on the other hand, is under the Red Sox' control through the 2018 season.)

Giles should only improve over the next few seasons, but his services are incredibly more valuable to a competitive team than a rebuilding one. Throughout the Phillies' 63-99 2015 season, Giles and Jonathan Papelbon were afforded only a combined 34 save opportunities. The number of chances in 2016 figures to be similar.

And so MacPhail, Klentak, and company need to consider the possibility of flipping their closer for longer-term assets. Among the most prominent questions for them to consider: When will the ninth innings of Phillies games matter again?

@jakemkaplan