Trea Turner takes early grounders with Matt Williams watching. (Alex Brandon/Associated Press)

Entering Thursday’s game against the Marlins, the Nationals trailed the Mets by 7.5 games with 17 left to play. Those are long odds, even for the most optimistic fans. The Nationals are not mathematically eliminated from the playoffs — the magic number sits at 10 — so they still have a chance. General Manager Mike Rizzo has already said the Nationals will play these remaining games to win.

Since the Mets’ sweep last week that dealt the Nationals their most crushing blow of the season, the call-up prospects have played only sparingly. The Nationals’ roster has grown to 36 players since rosters expanded on Sept. 1. Shortstop prospect Trea Turner was in the majors before then, but since roster expansion, prospects such as catcher Pedro Severino, infielder Wilmer Difo and starter A.J. Cole have been called up.

Turner has made one start when others were injured, and he has been used mostly as a late-game pinch runner, defensive substitute or in blowouts. Difo also entered Wednesday’s game when the Nationals’ lead was out of reach. Severino and Cole have yet to appear in a game this month.

“Depends on the game,” Manager Matt Williams said when asked about his plans to use the prospects and call-ups. “[Wednesday] night, we got just about everybody in the ballgame. But it depends. Depends on our health. Who is potentially available that day out of the bullpen. Adjustments that have to be made every single day. I can’t tell you a general philosophy because we just don’t know. [Thursday] presents a different story than [Wednesday] night. We’ll take all those things into account and go from there.”

Perhaps the Nationals may use more of those prospects if and when they are eliminated from the playoffs. Perhaps Cole, for example, could make a start so that the Nationals could assess his progress. He had a rough major league debut in April but finished the season strong at Class AAA Syracuse, his command, velocity and mechanics improved.

“It depends on our health and where we’re at,” Williams said. “Certainly can’t argue with the guys we’re running out there every fifth day. We’ll see what the games present. [Cole is] available long. If something goes — I hate saying this again — haywire or someone gets hit on the shin, then he’s available long and he’s available to do that.”