With Spring Training approaching, it's time for an in-depth look at the Pirates' roster. This is the final part of a series checking in on their current and future options at each position. Last but not least: the bullpen.
Big question: Who's going to get them to Felipe Rivero?
The ninth inning is Rivero's domain. The left-hander emerged last year as one of the Majors' best late-inning arms then signed a long-term extension, making him a foundational piece for Pittsburgh. But what will the bullpen look like in front of him? That's less clear.
Gone are the days of Mark Melancon and Tony Watson; this year's relief corps won't include a single member of the 2015 group that produced the Majors' lowest bullpen ERA. Instead, the Pirates have a lot of depth, but few proven commodities. Is it enough to hold whatever leads they get while supporting a young rotation without a guaranteed 200-inning starter?

The veterans:Daniel Hudson, George Kontos, Rivero
Ideally, the Pirates would like to see those three begin the season as their back-end trio. The right-handers will be the favorites to set up Rivero, who is entering his first full season as the closer.
Hudson is coming off a disappointing Pirates debut, which included a 4.38 ERA and 1.46 WHIP, despite 66 strikeouts in 61 2/3 innings. He had some strong stretches, especially in low-leverage situations and at PNC Park, but his walk rate climbed 4 percent as he fell out of the setup role they signed him for.
Around the Horn:Catcher | First base | Second base | Third base | Shortstop | Outfield | Rotation
Kontos was a no-risk waiver claim by the Pirates in August, and he finished strong in a late-inning role. Throw in the longtime Giant's impressive track record -- a career 3.00 ERA, 1.14 WHIP, postseason experience -- and he should play an important part in front of Rivero.
The new guys:Michael Feliz, Kyle Crick
Both throw hard, with Feliz's fastball clocking in at 96.3 mph, and Crick at 95.5 mph last season. The pair boasts high strikeout rates, with Crick averaging 10.2 per nine innings in the Minors and Feliz posting 12.8 per nine in the Majors. They'll both be around a while, Feliz through 2021, and Crick even longer.

Each has late-inning stuff, but lacks late-inning control. Command issues bumped Crick, a former Top 100 prospect, to the bullpen. Walks and homers contributed to Feliz's 5.13 ERA over 98 appearances in the Majors. If a change of scenery helps both figure it out, though, the Pirates will have the makings of a deep bullpen.
Depth starters:Steven Brault, Tyler Glasnow
GM Neal Huntington has occasionally mentioned the idea of these two serving a bullpen "apprenticeship" if they don't make the rotation. They'd remain in play as starters -- like Trevor Williams last year -- but could test themselves in the Majors instead of idling in Triple-A.
Brault seems like the better fit, as they could use a long man and another lefty. It'll be interesting to see if they actually carry both out of Spring Training, and what they might do if Glasnow, in particular, is successful out of the bullpen.
Middle relief candidates:A.J. Schugel, Dovydas Neverauskas, Edgar Santana, Josh Smoker, Jack Leathersich, Jordan Milbrath
If there's an open spot or two, there will be plenty of competition. The quietly effective Schugel is out of options. Neverauskas and Santana, viewed as future late-inning arms, gained valuable experience last season. Smoker and Leathersich are lefties with strikeout stuff.

Milbrath is a Rule 5 Draft pick with a fascinating profile -- a sidearm delivery, a high-velocity fastball and extreme ground-ball rates -- who might have to be returned to the Indians if he doesn't crack the Opening Day roster. There's also Nick Burdi, another Rule 5 righty who will need a spot this summer after he's completed the Tommy John rehab process.
Depth: That's already 14 pitchers, enough to fill two bullpens. Need more? Check out the pitchers on their list of non-roster invitees, including a handful of Minor League free agents. There's also right-hander Casey Sadler, who started once for the Pirates in 2015 before undergoing Tommy John surgery. Sadler returned last season and worked his way up to Triple-A, mostly out of the bullpen, where he should return this year.