The Padres' Kirby Yates and the Dodgers' Kenley Jansen headline the current stable of closers in the National League West, but it shouldn't be long before a changing of the guard begins to take place within the division.

Here's a look at who could be the future closer for each team:

D-backs: J.B. Bukauskas
Bukauskas was acquired by the D-backs from the Astros as part of the package for Zack Greinke just prior to last year's Trade Deadline. The right-hander, who is ranked Arizona's No. 10 prospect by MLB Pipeline, has an explosive fastball that can touch 98 mph and has a slider with a sharp bite to it. Command has been at times an issue for him, but missing bats hasn't. The D-backs' plan is to bring him along as a starter, believing that his four-pitch mix can make him effective in that role. But if they end up moving him to the bullpen at some point, he would certainly have the stuff to be an intriguing closer. -- Steve Gilbert

Dodgers: Brusdar Graterol
Eric Gagne had to be replaced and someday so will Jansen, the Dodgers' all-time saves leader who is signed through 2021.

A successor to Jansen had to be at least part of the thought process when the Dodgers acquired Graterol from the Twins in February for Kenta Maeda, and the Venezuelan looked even more like a late-innings option in Spring Training with a triple-digit sinking fastball and an easy delivery. MLB Pipeline has the 21-year-old right-hander ranked as the system's No. 5 prospect.

Although he's already had Tommy John surgery (2016) and a shoulder impingement last year, Graterol recovered to make a stretch impact for the Twins and had an overpowering inning in his only postseason appearance in Yankee Stadium, no easy assignment for a 21-year-old. In addition to the health issues, Graterol will need to watch his weight. But you can't teach 100 mph, so he's definitely closer material. -- Ken Gurnick

Giants: Reyes Moronta
The Giants entered Spring Training with a vacancy at closer after losing All-Star Will Smith to the Braves in the offseason. Moronta likely would have been the favorite to fill the role had he not suffered a devastating right shoulder injury that led to season-ending surgery to repair a torn labrum in September. Moronta resumed playing catch in February, but he wasn't expected to return to the Giants until August at the earliest. There will be plenty of question marks as Moronta works his way back from the second major arm injury of his career (he also underwent Tommy John surgery in the Minors), but the 27-year-old still profiles as a future closer after logging a 2.66 ERA over 132 career appearances in the Majors. -- Maria Guardado

Padres: Emilio Pagán
Yates might be the best reliever in the sport right now. But he's 33 and set to become a free agent next offseason, leaving the future of the Padres' closer role in some doubt. Then again, it helps when you've got one of the deepest bullpens in the sport to pick your next closer from. Pagán has already filled that role, saving 20 games for Tampa Bay last season, while posting a 2.31 ERA with a 36 percent strikeout rate. Right now, Pagán is the heir apparent -- though electric young arms like José Castillo, Andres Muñoz, Michel Baez, Anderson Espinoza and Javy Guerra might challenge for the closer role down the road. The Padres, of course, would still love to have Yates on board for a few more seasons. But they've got options for the back end of the bullpen no matter what happens. -- AJ Cassavell

Rockies: Jairo Díaz
The plan was for Díaz to be developed as a closer when the club acquired him from the Angels after the 2015 season. But Tommy John surgery cost him the '16 season. He was limited to four Major League games in '17 while recovering from the surgery and spending time with his wife before cancer took her life. After gradually working his way back in '18, he blossomed in '19 -- 63 strikeouts in 57 2/3 innings, and five saves at season's end. Diaz's power fastball and a developing slider, as well as a desire to eventually fill the role, point to ninth-inning opportunities. -- Thomas Harding