(Matt Slocum / AP)

Ian Desmond has probably been the Nationals best player this season, and he has certainly been their most durable, having played 99 of their 100 games. He will miss only his second game of the season tonight to heal a nasty blister on his left hand. Desmond developed the blister during the Nationals’ workout Thursday before the second half opened, and he ripped open the skin on his hand sliding into second base as he stole a base Saturday against the Dodgers.

Desmond tried to play through the blister, wrapping tape around his hand and using a glue-like substance. But the gash refused to heal, and so he wants to heal the skin before it becomes a more significant problem.

In the three games since he tore open the blister, Desmond has gone 0 for 10 with one walk and four strikeouts. Manager Davey Johnson said the blister was so inflamed Tuesday night that Desmond would not have been able to hit if his turn came up in the ninth inning.

“It was really looking bad last night,” Johnson said.

Desmond said he expects to return Thursday in the series finale against the Pirates. Johnson, though, suggested it could take longer.

“It may need a couple days for that thing to dry out for Desi,” Johnson said. “But we’ll see.”

In place of Desmond, who had played 56 consecutive games since May 20, Anthony Rendon will move from second base to shortstop. Steve Lombardozzi will take over at second base, his first start since July 13.

Johnson informed Rendon last night he would play shortstop, where he has played precisely once as a professional in the regular season. Rendon also received a smattering of playing time at shortstop this spring training.

The Nationals already wedged Rendon into unfamiliar territory when they made him their everyday second baseman to replace the floundering Danny Espinosa. Rendon had only played second base a handful of times since Little League.

The lack of experience has showed at times – last night, Rendon botched a crucial double play when he dropped Ryan Zimmerman’s throw. Overall, though, Rendon has been impressive as he transitions not only to a new level, but a new position.

“Playing a new position at this level, he’s done great,” Johnson said. “Not only is he learning to play a position, but the adjustment you have to make up here. They’ll be trying to find different ways to get you out, and you have to make adjustments.”

Johnson said Rendon has hit the period of a rookie’s first season when the league has adjusted to him, and it’s time for him to counter. In the first 26 games of his career, Rendon hit .354/.402/.485. In the 22 games since, Rendon has hit .179/.233/.333.

“He’s smart,” Johnson said. “He’ll figure it out.”