The Nationals have agreed to terms with Wilmer Difo on a 2020 contract that will pay the utility infielder $1 million if he's on the big league roster, a source familiar with the deal confirmed this afternoon.

The signing, which was first reported by USA Today, comes one day before Major League Baseball's deadline for clubs to tender contracts to all arbitration-eligible players. It means Difo and the Nationals will avoid going to arbitration, but it doesn't guarantee him the full $1 million.

One-year deals for players who have yet to reach free agency typically are not guaranteed. If a team releases a player who falls under this category within the first 16 days of spring training, he receives only one-sixth of his salary. Reliever Sammy Solís suffered that fate this year after agreeing to a non-guaranteed, $850,000 contract over the winter.

Thus, Difo will have to earn his way onto the Nationals' opening day roster, with no margin for error. The 27-year-old is out of options and thus can't be sent to the minors without first clearing waivers.

Difo actually spent most of 2019 at Triple-A Fresno, demoted in mid-May after struggling while starting at shortstop in place of the injured Trea Turner. He returned in September and appeared in four games down the stretch before watching the postseason from the bench.

Overall, the switch-hitter batted .252 with two homers, eight RBIs and a .628 OPS in 43 major league games this season while earning $581,100, slightly more than the league minimum. His struggles in the field contributed to a WAR of -1.1, according to Baseball-Reference.com's formula.

Because he now has more than three years of big league service time, Difo qualified for arbitration this winter and had the right to negotiate his salary. Had the two sides not been able to come to terms on their own, they would've had to go to arbitration in February.