By Steve Ginsburg

WASHINGTON (Reuters) - Stephen Strasburg's season will end after 160 innings even if the success-starved Washington Nationals are involved in a playoff push, manager Davey Johnson insisted Wednesday.

The All-Star right-hander is 10-4 this season with a 2.66 earned run average and a league-leading 135 strikeouts but the flame-thrower has already pitched 105 innings for the National League East division leaders.

"That decision (to limit his innings) was made by people a lot smarter than me," Johnson said on Wednesday before the Nationals faced the New York Mets. "I'm not fighting it. When that time comes, he's done."

Strasburg had elbow surgery late in the 2010 season and the Nationals said they set the 160-inning limit in spring training to ensure their ace is around for the long haul.

At this rate, Strasburg's season will be put on ice in early September.

Last week, Strasburg said, "They're going to have to rip the ball out of my hands" during a pennant race but he now bristles at questions on the issue.

"I've been asked so many times, I have the same response," the 23-year-old Strasburg said on Wednesday without taking his eyes off the clubhouse television. "I don't know."

"It's something that you're going to have to talk to the general manager (Mike Rizzo) or Davey about. They might have a little more information for you."

When asked whether he might miss a few starts to stick around for the stretch drive, Strasburg said, "Nothing's been said to me, man. I'm just pitching. I don't know what to say."

Johnson insists Strasburg will continue to pitch his normal routine, although he admitted he sometimes pulls the third-year big-leaguer from games a little early to limit his innings.

"It would be very unfair to change his work ethic," said Johnson. "He needs to pitch every fifth day. Any disruption of that, as far as I'm concerned, would lead to possible injury."

The Nationals have an N.L.-best 52-36 record and are seeking their first winning season since the franchise arrived in Washington from Montreal in 2005.

(Editing by Frank Pingue)