After breakthrough season, Rainey looks like future closer

Our offseason player review series continues today with Tanner Rainey, who ascended to a prominent bullpen role before getting hurt.

PLAYER REVIEW: TANNER RAINEY

Age on opening day 2021: 28

How acquired: Traded from Reds for Tanner Roark, Dec. 2018

MLB service time: 1 year, 158 days

2020 salary: $572,200 (prorated $211,926)

Contract status: Under team control, arbitration eligible in 2022, free agent in 2025

2020 stats: 1-1, 2.66 ERA, 20 G, 0 SV, 20 1/3 IP, 8 H, 6 R, 6 ER, 4 HR, 7 BB, 32 SO, 1 HBP, 0.738 WHIP, 175 ERA+, 3.78 FIP, 0.3 fWAR, 1.1 bWAR

Quotable: "His stuff is electric. When he gets to two strikes, everyone knows he's got a really good slider. But they've got to realize he can also throw a fastball. Now that he's locating his fastball, it's tough. That's a tough at-bat for a hitter." - Manager Davey Martinez on Rainey

2020 analysis: Compile a list of bright spots for the 2020 Nationals, and Rainey would end up very high on the list. There were vibes of optimism surrounding the right-hander when the season began. By the end, there was no doubt he's going to be an important figure in the back end of the bullpen for a while, as long as he stays healthy.

As the more experienced late-inning arms in the Nats 'pen either struggled or dealt with injuries, Rainey kept performing at a high level and earned a prominent role. He allowed just one run and two hits through his first 12 appearances, despite an increasingly heavy workload that at one point included five outings in six days.

With an upper-90s fastball and devastating slider, Rainey was effective against hitters from both sides of the plate. He actually fared better against left-handed batters, who collectively produced a paltry .107/.138/.286 slash line against him. And he took it to another level in the biggest situations. With runners in scoring position, opponents hit .095 (2-for-21). With two outs and runners in scoring position, they hit .000 (0-for-9).

The extensive workload may have caught up with Rainey near season's end, though. During a Sept. 4 appearance in Atlanta that marked his third straight day pitching, he suffered his one and only blown save via a Freddie Freeman grand slam. He would go on to serve up homers in three of four appearances, after which he complained of a sore forearm. The Nats placed him on the injured list with a flexor strain, and he remained there through the end of the season.

2021 outlook: The Nationals insisted Rainey's injury wasn't serious and they were being extra cautious holding him out of the season's final two weeks. If that proves to be true, there shouldn't be any concern heading into 2021, but certainly there will be plenty of eyes on him during spring training to make sure he is indeed 100 percent healthy.

The Nationals will be expecting a lot from Rainey next year. Depending on their offseason bullpen maneuvers, it's not out of the question he could take over the closer's job. If not on opening day, he's certainly a candidate to assume that role at some point along the way.

Rainey has the stuff to pitch the eighth and ninth innings, of that there's no doubt. He also seems to have the mentality needed to handle that pressure-packed role, something he began to show late in 2019 and really showed in 2020. Now he needs to show he can do it consistently over a full 162-game season.

As is the case with everyone else in the Nats bullpen, Rainey will be helped if he has plenty of help around him. Martinez had little choice but to overwork him this year. That could have led to the forearm injury. The Nationals can't afford to have that (or worse) happen in 2021. If Martinez can map out a schedule that leads to 60-to-65 appearances in high-leverage spots, Rainey could be primed for a fantastic season.