Aroldis Chapman is a Yankee. He and Dellin Betances will form the best 1-2 punch in baseball next season. However, the Yankees will carry five other relief pitchers next season, and will probably call up at least twice that many during the season. Let's see if we can map out those twelve pitchers. I'm going to avoid converting any minor league starting pitching (with one exception) to the bullpen, since the Yankees are desperate for starting pitching right now.
I think the Yankees have the potential to pull 3-4 dominant relief pitchers out of this group to form a really special bullpen, but I wouldn't be shocked to see relievers 3-6 fail in the early season before the guys farther down the depth chart start to be given real chances.
1-2: Aroldis Chapman and Dellin Betances. You know those guys.
3-4. Tyler Clippard and Adam Warren. They are the veterans of the Yankee bullpen, and they will be given the chance to break camp with the team as long as they stay healthy. Problem is, I'm not sure either is any good anymore. Clippard posted a 3.57 ERA last season, barely above the 3.93 league average, against a 4.21 FIP. Warren was worse. Hopefully both rebound, but I wouldn't be shocked if neither is on the MLB roster by September.
5. One of Luis Cessa, Luis Severino, or Chad Green - The Yankees need to fill their back two rotation spots. The loser of that probably goes to the bullpen, although I could see any of these guys back at Triple-A too. If Severino ends up in the bullpen, my bet is it is for good, and Severino becomes an ace reliever. The other two guys would be long men.
6. Richard Bleier - Lefties hit .150/.209/.200 off Bleier during his brief MLB debut in 2016, and .196/.244/.241 in the minors. We'll see if he can sustain that, especially considering his career minor league K/9 of 5.0. I'm skeptical (he's 29), but he'll get the first shot at middle relief innings against left handed batters. The Yankees definitely have room to add a Boone Logan type.
7-8 Johnny Barbato and Nick Goody - The Yankees used a lot of forgettable right-handed relief pitchers last season. Most of them are off the 40-man, but these guys stuck around. Both were terrible in small samples in the majors, but excellent at Triple-A. Goody's stats were particularly eye-popping: 1.93 ERA, 0.68 WHIP, 13.5 K/9 1.5 BB/9, after an excellent 2015. Goody deserves an extended shot.
9-10 Jonathan Holder and Ben Heller - Now things get interesting. Holder was flat-out dominant in the minors last season: 65 innings with 14 K/9 and 1 BB/9. He started all the way down in High-A and finished in the major leagues. At Triple-A, he allowed just two runs and seven baserunners in 35 innings. At one point, Holder struck out 11 Triple-A batters in a row. He's not a closer with the stuff to blow guys away, but the results are elite.
11. Giovanny Gallegos. Not going to lie, I had no idea who Gallegos was until the Yankees added him to the 40-man roster after the season. The Yankees originally signed him as a starting pitcher out of Mexico. He sat in the low-90s, and attracted a little bit of attention at the time. He never found much success in the minor leagues as a starter, but has been lights-out since being converted to the bullpen in 2015. I can't find a scouting report since the conversion, but the stat line is impressive; in 2016 between Double-A and Triple-A, he pitched 78 innings (42 games) with a 1.27 ERA, 12.0 K/9, 2.0 BB/9. He had a bit of a reverse platoon split; righties hit .216/.274/.346 while lefties hit .128/.162/.208. I wouldn't be shocked if he breaks camp with the team.
12. Mark Montgomery. He's been around forever. After the the matriculation through the minors of David Robertson and Mark Melancon, Montgomery was on track to the the Next Yankee Relief Ace Prospect in 2012. Scouts said he had one of the best sliders in the minors, and he quickly climbed to Double-A. Then, Montgomery hurt his shoulder, and he hasn't been the same since. However, Montgomery is still just 26 years old. He has bounced around the high minors since 2013 with reduced velocity and poor control. He got back on track in 2016: 45 innings with a 2.56 ERA, 12.4 K/9 4.3 BB/9. I think he could still become a Shawn Kelly type, but I'm assuming he's the low man on the depth chart.