Hard-throwing Rainey showed potential to pitch late innings

As our offseason coverage kicks into high gear, we're going to review each significant player on the Nationals roster. We continue today with Tanner Rainey, who by season's end had established himself as one of the more reliable members of the bullpen.

PLAYER REVIEW: TANNER RAINEY

Age on opening day 2020: 27

How acquired: Traded from Reds for Tanner Roark, December 2018

MLB service time: 158 days

2019 salary: $555,000

Contract status: Under club control, could be arbitration-eligible in 2022, free agent in 2026

2019 stats: 2-3, 3.91 ERA, 52 G, 0 SV, 48 1/3 IP, 32 H, 22 R, 21 ER, 6 HR, 38 BB, 74 SO, 4 HBP, 1.448 WHIP, 118 ERA+, 4.37 FIP, 0.2 fWAR, 0.6 bWAR

2019 postseason stats: 0-0, 6.75 ERA, 9 G, 0 SV, 6 2/3 IP, 3 H, 5 R, 5 ER, 1 HR, 5 BB, 6 SO, 0 HBP, 1.200 WHIP

Quotable: "The biggest thing with him, obviously, was the walks. But he's got electric stuff and - when he throws strikes - he's tough to hit." - Davey Martinez on Rainey

2019 analysis: Only token attention was paid to the prospect the Nationals got in exchange for Roark last winter, a hard-throwing reliever who had all sorts of command problems in his first (brief) big league experience with the Reds. By the end of his first season in the Nats organization, everyone knew who Rainey was, and most were intrigued by his stuff and improved ability to harness it.

Though his numbers at Triple-A Fresno weren't all that impressive, the Nationals were desperate for bullpen help in mid-May, so they took a chance on Rainey and summoned him to New York to help solve the team's biggest problem area. He made his debut May 20 and tossed a scoreless sixth inning, prompting Martinez to give him a shot in a higher-leverage spot the next night. Rainey would promptly blow an eighth-inning lead and suffer one of the team's four heartbreaking losses at Citi Field in the series that left it at its 19-31 low point.

Rainey wouldn't see a lot of high-leverage spots again for a while, but he slowly earned Martinez's trust to pitch in big situations again, typically the seventh inning. And as the postseason played out, the rookie right-hander became Martinez's most trusted reliever after Daniel Hudson and Sean Doolittle. He would go on to record big outs in the National League Division Series and NL Championship Series clinchers, plus Game 2 of the World Series.

2020 outlook: Given his electric arm - not to mention the lack of other proven arms currently under contract - Rainey is going to be high on the organizational depth chart heading into spring training. The Nationals most likely will view him as a top option for a setup role to begin the season, with the potential to earn the ninth-inning job at some point in the future.

Rainey certainly has the stuff - a fastball that averaged 98 mph, a slider that averaged 87 mph - to do it. But he has to show that he can consistently throw that stuff near the strike zone. He was the rare pitcher who actually gave up more walks than hits, nearly one per inning.

There were encouraging signs in the postseason, though, and Rainey did show an ability to handle those high-pressure situations. He's far from a finished product, of course. And he shouldn't be considered a sure thing at this point. But there's plenty of reason to be optimistic about this flamethrower and hope he does develop into a consistently dominant late-inning reliever for the Nationals.