The immediate question after the Nationals traded Tanner Roark Dec. 12 for a reliever was: What now?

The market wasn't sparkling with options. Matt Harvey had recently signed an $11 million deal with the Angels. Trevor Cahill joined him on a $9 million deal. The mediocre market set price points while the Nationals pursued a Roark replacement.

They landed one Thursday when the organization agreed to terms with free agent right-hander Anibal Sanchez, pending a physical, NBC Sports Washington has confirmed. Sanchez’s deal is for two years with a club option in 2021, according to a source. Its value is $19 million for the first two years, and $12 million for the option year, according to multiple reports.

Sanchez is coming off a year that rejuvenated his reputation. His 2.83 ERA was his lowest since 2013. The veteran increased his slider and cutter usage -- often mistaken for each other when pitches are charted -- and reduced his fastball output to a career low, dropping it a massive 10.8 percent year over year from 2017.

Sanchez used his fastball just 38 percent of the time last season. His uptick in off-speed pitches landed him a new, multi-year contract a mere two years after he delivered a 6.41 ERA.

The argument for trading Roark was three-fold: His cost, approximately $10 million after arbitration, was too much for his results and position in the rotation. He was entering the final year of his contract, so trading him this offseason provided some form of return for a pitcher unlikely to be back. He under-performed his last two seasons.

Signing Sanchez didn't save any money, and is a clear roll of the dice. His 2018 results popped up following four consecutive years of decline. He has not thrown more than 180 innings since 2013, a mark Roark reached annually. Sanchez also allows a lot of home runs.

But, the Nationals are gambling that even in a regression from 2018, Sanchez will provide them better results than Roark had the prior two seasons. How vast is Sanchez’s fluctuation the last two seasons? He went from a 70 ERA-plus with Detroit in 2017 to 143 last season with the Braves. Last season’s mark is better than $140 million man Patrick Corbin in 2018.

Sanchez is entering his age-35 season. Typically, this is not a time of improvement. Good news for him is his results held through last season as opposed to two dominant months coupled with middling ones. Sanchez pitched to a 2.48 ERA in June when he entered the Braves’ rotation. He went 3.48, 2.93, and 2.25 in the months that followed, making at least five starts each month.

His effectiveness is intriguing as the league works to counter the launch-angle era. A phrase more commonly being uttered is “softer is better” for starting pitchers, since staffs had lurched so far toward being filled with only hard throwers.

Sanchez’s pitty-pat arsenal irritated and sat down the Nationals last season. He finished with a 1.50 ERA in 18 innings against Washington in 2018. So, it has first-hand knowledge of Sanchez’s effectiveness.

The deal also pulls another piece away from the division-winning Braves. Washington signed catcher Kurt Suzuki earlier in the offseason. It can pair him with Sanchez as well as tap both for knowledge of what the Braves are trying to do in order to get Nationals hitters out.

Lastly, the signing locks down the lone remaining full gap in the roster. Washington could still sign a full-time second baseman, but has a platoon in place if not. The Nationals are also set in the outfield if Bryce Harper goes elsewhere.