Jeremy Hellickson will make his Nationals debut Monday. (Gail Burton/Associated Press)

When the Washington Nationals begin a crucial-for-mid-April three-game series at the New York Mets on Monday, they’ll do so with an unfamiliar face on the mound. Jeremy Hellickson, who signed a minor league deal during spring training, will make the start, Manager Dave Martinez announced Sunday.

Martinez said the team hadn’t made a corresponding roster move, but Hellickson will replace A.J. Cole in the rotation. The Nationals could option a reliever and move Cole to the bullpen to serve as the long man, or they could risk losing Cole by designating him for assignment since he doesn’t have any options remaining.

Hellickson, 31, has been in West Palm Beach, Fla., pitching in live extended spring training games and throwing side sessions at the Nationals’ facility. The veteran right-hander made 30 starts for the Phillies and Orioles last season, pitching to a 5.43 ERA across 164 innings. The Nationals won’t ask for much from him; they simply need a fifth starter who can consistently eat innings and avoid overtaxing the bullpen.

Cole had two attempts to win the job outright — if it ever really was a competition. He flopped in the first, allowing 10 runs in 3 2/3 innings against the Atlanta Braves on April 3. Washington skipped his next turn in the rotation, but he rebounded Wednesday by attacking the strike zone more. The results were encouraging: two runs on three hits and two walks against the same Braves team that crushed him eight days earlier.

The outing, however, wasn’t enough for Cole to keep his spot in the rotation. Whether he remains with the club at all will be announced Monday. Instead, the Nationals will entrust Hellickson on the road against the first-place Mets, who are six games ahead of them in the National League East.

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