Will Nats tender contract to up-and-down Solis?

WASHINGTON -- The potential in the left arm of Sammy Solis has tantalized the Nationals since they selected Solis in the second round of the 2010 MLB Draft, their next pick after taking Bryce Harper first overall.
When Solis is right, his fastball is electric, with a curveball and a changeup serving as strong complements. But for long stretches of the past two seasons, Solis has not been right. Whether injury or ineffectiveness has been the cause, Solis had a 6.20 ERA from 2017-18.
The Nats have seven arbitration-eligible players this season and must decide by 8 p.m. ET on Friday if they want to tender them contracts. Six of them -- Anthony Rendon, Trea Turner, Tanner Roark, Joe Ross, Michael A. Taylor and Kyle Barraclough -- are no-brainers. Solis' future is not as simple.
Solis is first-year arbitration-eligible this season after making $560,300 in 2018. His salary will not be outrageous, but the question is whether Solis, 30, can be an effective reliever. He spent time on the disabled list in each of the past three seasons and he is also out of options. The Nationals will need to decide whether Solis can earn a spot in the Opening Day bullpen, and offering him a contract could delay that decision until Spring Training. Or they could cut ties with him now.
Solis' struggles with left-handed hitters were particularly frustrating for the Nats last season. Manager Dave Martinez used him against lefties repeatedly, especially late in the season after the team's postseason hopes had dwindled, but the results were not good. Solis faced 88 lefties last year, and they clubbed five home runs with a .993 OPS against him. Single-season splits for a reliever can be misleading, but the trend still is troubling. In his career, lefties own a 108 OPS+ against Solis, compared to a 94 OPS+ for righties.
"Just keep grinding. Keep going through the process I've had my whole career of just working hard and trusting myself," Solis said in September, when asked about his struggles. "I know my teammates trust in my abilities. So just go out and keep pitching, that's really all I can do."
At his best, Solis can be a hard-throwing, multi-inning fireman, the kind of versatile reliever featured in most playoff bullpens. In 2016, he posted a 2.41 ERA with 10.3 strikeouts per nine innings in 37 games. At times, he has been one of the Nationals' most trusted relievers, pitching in big spots in the postseason in 2016 and '17. Martinez leaned on him heavily to begin the '18 season.
But the question is whether the Nats believe Solis can regain that form.
"I told him I'm not giving up on him," Martinez said in late September. "And he knows that. ... Sammy earlier in the year helped us win a lot of games. And then he kind of lost it a little bit. But I'm not giving up on him. I'm not."