WEST PALM BEACH, Fla. -- In a span of four days last July, the Astros drastically strengthened the back end of their bullpen for the stretch drive by acquiring veteran right-hander Ryan Pressly from the Twins and All-Star closer Roberto Osuna from the Blue Jays.

The Astros coveted Pressly and his swing-and-miss stuff as much as they did Osuna, who’s considered one of the best young closers in the game and is under club control for several more years. Pressly came with plus-plus stuff and a solid track record and then took his game to another level with the Astros by developing an elite spin rate on his curveball, which is one of the best in baseball.

Osuna, who has a vast arsenal of pitches for a closer, posted a 1.99 ERA and saved 12 games with the Astros in the regular season. Pressly had a 0.77 ERA and a 0.600 WHIP in 26 games with Houston, striking out 32 and walking three. He ended the season with a 21-game scoreless streak.

 “This is the deepest our ’pen has been at the start of season,” Astros manager AJ Hinch said, “where we feel really, really excited about Osuna and Pressly and [former All-Stars Will] Harris and [Chris Devenski]. And whoever doesn’t end up being the fifth starter, it’s not as if he’s going to be the last man in the ’pen. These are really big arms that are going to try to find a spot for some innings.”

With Osuna and Pressly, the Astros have one of the best setup/closer combinations in the game and perhaps one of the best in Astros history. Here’s a look at some of the Astros’ other vaunted back-end bullpen combinations in team history:

1980 Astros -- The addition of Nolan Ryan to a starting rotation that already included J.R. Richard and Joe Niekro gave the Astros a terrific pitching staff, which is why they won the National League West and made the playoffs for the first time (despite Richard’s midseason stroke). The bullpen was just as filthy. Veteran lefty Joe Sambito handled the majority of closing duties, with support from Frank LaCorte and rookie Dave Smith, who went on to set the franchise record for saves later in his career. Smith (199) and Sambito (72) are ranked second and fifth, respectively, on the club’s all-time saves list.

1986 Astros -- Smith had blossomed into an All-Star closer for the Astros’ second NL West division title team in ’86, saving a career-high 33 games with a 2.73 ERA. Twenty-two-year-old rookie Charlie Kerfeld came out of nowhere and handled the setup duties nicely, posting a 2.59 ERA and winning 11 games, with seven saves.

• Hinch leaning toward opening with 12 pitchers

2001 Astros -- Fireballing lefty Billy Wagner, who holds the club record with 225 career saves and built a surprisingly strong Hall of Fame resume, saved 39 games -- then a franchise single-season record -- in helping the Astros win the NL Central for the fourth time in five years. Octavio Dotel was a devastating setup man, posting a 2.66 ERA with 145 strikeouts in 105 innings.

2005 Astros -- The Astros won the NL pennant in ’05 because of their pitching staff, led by starters Roy Oswalt, Andy Pettitte and Roger Clemens. Their relief was just as strong in the regular season. Brad Lidge posted the second-highest save total in franchise history, with 42, and Dan Wheeler mustered a 2.21 ERA in the setup role. After Lidge gave up the infamous homer to slugger Albert Pujols in Game 5 of the NLCS to keep the Cardinals alive, Wheeler was on the mound to close out Game 6 in St. Louis and seal Houston’s first pennant.

2017 Astros -- Ken Giles, traded last year to the Blue Jays for Osuna, was terrific in the 2017 regular season, though Astros fans couldn’t forget his playoff shortcomings. He saved 34 games that year with 83 strikeouts in 62 2/3 innings. All-Star Chris Devenski had a 2.68 ERA and 100 strikeouts in 80 2/3 innings as the primary setup guy later in the season.