Surprisingly successful Miller should be part of 2019 bullpen

As our offseason coverage kicks into high gear, we're going to review each significant player on the Nationals roster. We continue today with Justin Miller, a surprisingly successful addition to the bullpen.

PLAYER REVIEW: JUSTIN MILLER

Age on opening day 2019: 31

How acquired: Signed as minor league free agent, January 2018

MLB service time: 2 years, 129 days

2018 salary: $545,000

Contract status: Under team control in 2019, arbitration-eligible in 2020, free agent in 2023

2018 stats: 7-1, 3.61 ERA, 51 G, 2 SV, 52 1/3 IP, 42 H, 22 R, 21 ER, 10 HR, 17 BB, 60 SO, 2 HBP, 1.127 WHIP, -0.1 fWAR, 0.9 bWAR

Quotable: "I got to give credit to the scouts and whoever brought him over here. I don't know who. Obviously, Rizzo was a part of it, and everybody else who suggested he come over and pitch, because he's gotten a lot of big outs and he's just having fun in the moment." - Ryan Madson on Miller, June 13

2018 analysis: How off-the-radar was Miller at the start of the season? He wasn't even in big league camp, wasn't even called up to pitch in one Grapefruit League game as so many other minor leaguers are every spring. But then the journeyman right-hander tossed 13 2/3 scoreless innings to begin the season for Triple-A Syracuse, allowing only three hits while striking out 23 batters, and the Nationals had no choice but to notice.

Miller was promoted to the majors in late May and picked up right where he left off in the minors. Through his first eight outings, he owned a 0.00 ERA and a 4-0 record, surrendered only two hits with zero walks and struck out 21 of the 34 batters he faced. In short, he was a completely out-of-nowhere revelation.

That rate of success, of course, couldn't be sustained. And sure enough, Miller then gave up runs in five consecutive outings before settling into something of a groove. Over his final 31 appearances, he had a 3.25 ERA and 1.084 WHIP, establishing himself as one of Davey Martinez's more trusted relievers in late-inning situations.

2019 outlook: How did a 31-year-old with a career 4.99 ERA suddenly turn into a dominant reliever with a new organization? In Miller's case, the key difference was in his mechanics. With the Nationals, he started throwing across his body, allowing him to better hide the ball and get more movement on his pitches. The question now is whether this was a permanent breakthrough or only a brief flash of success.

The Nats are going to find out, because Miller isn't going anywhere. Despite his advanced age, his lack of big league experience means he's not even arbitration-eligible yet. So not only is he under contract for four more seasons, he'll still make a six-figure salary in 2019.

To sustain success, Miller will need to do a better job keeping the ball in the park. He surrendered all 10 of his homers during a stretch of only 34 1/3 innings over the summer. Seven of those came off fastballs, so it really is all about command of his bread-and-butter pitch.

The Nationals already have Sean Doolittle closing, they already acquired Kyle Barraclough to fill a setup role and they're almost certainly going to be in the market for more late-inning relievers this winter. So Miller isn't going to be penciled into one of those high-profile roles. But the success he had this season and his ability to pitch multiple innings figure to make him a valuable member of the 2019 bullpen in some capacity.