PITTSBURGH -- Two years ago, the Pirates employed the Majors' most effective bullpen. The group, led by Mark Melancon, Tony Watson and Jared Hughes, quietly posted a 2.67 ERA, the best in the big leagues in 2015.
Pittsburgh has undergone a complete bullpen makeover since then, ending the 2017 season without a single member of that relief corps on its roster. But with lights-out lefty Felipe Rivero returning as the closer, the club believes it has the core of another strong bullpen in place heading into next season.
But Rivero is the only experienced lefty reliever on the 40-man roster, so expect the Pirates to add at least one more left-hander before Spring Training. They could take their chances with Jack Leathersich, Nik Turley, starter Steven Brault or perhaps another waiver claim, Rule 5 Draft pick or Minor League free agent.
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There are a handful of experienced lefty relievers available in free agency, however, including Jake McGee, Boone Logan and Brian Duensing -- not to mention former Pirates Francisco Liriano and Watson. The Pirates also have been in contact with the agent for recently non-tendered lefty Xavier Cedeno, according to the Pittsburgh Tribune-Review.
For the most part, though, the Bucs' 2018 bullpen should look much like it did at the end of last season. Rivero, who has emerged in Pittsburgh as one of baseball's most dominant relievers, will be the closer without question from Day 1 after beginning last year as a setup man for Watson.
In front of Rivero are veteran right-handers George Kontos and Daniel Hudson and young righties Dovydas Neverauskas and Edgar Santana. It remains to be seen how they will line up, but Kontos seemingly has the inside track to a setup job, given his strong track record and late-season success with the Pirates.

Hudson struggled early on as a setup man last season and eventually assumed a middle-relief role. He posted a 3.43 ERA and held opponents to a .211/.339/.373 line the last four months of the year, generally pitching better in lower-leverage spots.
Neverauskas and Santana had up-and-down debuts, but the Pirates view both as future late-inning relievers. Neverauskas finished with a 3.91 ERA and 1.26 WHIP in 25 1/3 innings, while Santana posted a 3.50 ERA and 1.56 WHIP over 18 innings. Manager Clint Hurdle was encouraged by the experience both young relievers gained in September.
"I thought there was growth there," Hurdle said at the end of the season. "I think the prior experience has helped them transition in really well, and they played a larger role this last time in Pittsburgh. More significant innings, more leverage innings."

The Pirates have plenty of internal options to fill out the group. Right-hander A.J. Schugel auditioned for Hughes' former "fireman" role late last season, and Johnny Barbato bounced between the Majors and Triple-A. General manager Neal Huntington has mentioned the possibility of putting their sixth starter in the bullpen, as they did last April with Trevor Williams.
But for now, the Pirates will build their next bullpen around Rivero, Kontos, Hudson, Neverauskas and Santana.

"That's a pretty good foundation of a bullpen, relying heavily on some young relievers," Huntington said in October. "We know there are ups and downs with young players, and we'll look to continue to supplement that with some of the guys out of the rotation. … We'll look to be opportunistic in trades and the free-agent market."