(Jonathan Newton/The Washington Post)

The Nationals are planning to add three pitchers and four or five position players as September call-ups, Manager Davey Johnson said. The likely list of reinforcements will likely be as notable for who is not coming as for who is.

The Nationals are likely to not call up Danny Espinosa, who started the season as the Nationals’ firmly entrenched second baseman and has struggled at Class AAA Syracuse since early June. Espinosa, who has hit .213/.280/.287 in 44 games, will incur a significant financial blow by not earning a call-up.

Espinosa will likely fall days short of qualifying for “Super Two” status and becoming eligible for salary arbitration this offseason. Rather than earning a lucrative salary, Espinosa will again earn the league minimum if he plays in the major leagues next year.

As for Nationals minor leaguers heading to the majors, Johnson said the Nationals will add the three pitchers first. Left-handers Ian Krol and Xavier Cedeno and right-hander Erik Davis are believed to be the three relievers the Nationals will add.

The Nationals will wait another two days, until minor league seasons end, to make their call ups with position players. “There’s nobody that will be coming up that hasn’t played for me before,” Johnson said. “Your call-ups, you reward people for good years.”

The most intriguing expected call-up may be infielder Zach Walters, who has hit 29 homers this season. The Nationals will need to add to Walters to the 40-man roster, which is not much of an obstacle. The Nationals have two spots open, and they would have needed to add Walters this winter, anyway, to protect him from the Rule 5 draft.

The Nationals are also expected to call up catcher Sandy Leon, outfielders Eury Perez and Corey Brown and utility man Jeff Kobernus. All four have played for the Nationals before, with Perez and Kobernus receiving brief major-league stints this season.

Leon is the only catcher on the Nationals’ 40-man roster behind Wilson Ramos and Jhonatan Solano. Kobernus led Class AAA Syracuse with a .324 average. Perez could be effective as a pinch runner. Kobernus’s speed and versatility will make him a useful roster piece. Corey Brown has hit 19 homers at Syracuse this year and would be a call-up for the third straight season.