WASHINGTON -- The decision on whether the National League East-leading Washington Nationals will shut down prized starter Stephen Strasburg apparently has been made. The when is all that remains.

General manager Mike Rizzo told ESPN Wednesday that he alone will decide when Strasburg's 2012 All-Star season will end, and that it's not necessarily at the 160-inning mark that has been talked about so often.

Strasburg underwent reconstructive elbow tendon surgery (known more commonly as Tommy John surgery) toward the end of his 2010 rookie season. He managed to return toward the end of last season, and pitched in only 44 combined innings that included minor league rehabilitation outings.

"There is no magic number," Rizzo said. "It will be the eye test. (Manager) Davey (Johnson) won't decide and ownership won't decide. It will be the general manager, and that's me."

Strasburg is enjoying a spectacular first full season in the majors, with a 10-4 record and 2.66 ERA while leading the NL with 135 strikeouts.

With the Nationals 4½ games ahead of second-place Atlanta and the addition of a playoff spot in each league, it appears the District of Columbia might be able to enjoy its first postseason appearance since 1933, when the original Washington Senators (now the Twins) reached the World Series.

The starting pitching of Strasburg, Gio Gonzalez, Jordan Zimmermann, Edwin Jackson and Ross Detwiler is acknowledged as the primary reason for the Nationals' sudden rise, but subtracting ace Strasburg down the stretch could significantly alter the makeup of the rotation -- especially in a five- or seven-game playoff series.

Nonetheless, Rizzo said he is looking out for the welfare of the right-hander, who will turn 24 Friday, as well as the long-term outlook of one of baseball's youngest rosters, one that appears set to make postseason runs for several years.

"When we signed Stephen I made a promise to him and to his parents that I would take care of him and that's what we are going to do," Rizzo said. "I told them we would always do what's best for him. This is a kid who has never pitched more than 123 innings in a year.

"We are looking at not only competing for the playoffs this season, but also in '13, '14, '15 and beyond. Stephen is a big part of those plans and I will not do anything that could potentially harm him down the road."

As for those thinking Strasburg could be given a few weeks or a month off, then return, Rizzo says don't count on that happening.

"When it happens, Stephen will not pitch again until spring training (in 2013)," he said. "We tried something similar with Zimmermann last year and he just could not get going again. We won't make the same mistake."

Zimmermann underwent similar surgery in 2010 and was shut down after 161 innings last year in late August. Of course, that decision wasn't met with nearly as much public debate as Strasburg's potential shutdown because the Nationals were buried deep in the NL East standings at the time.

"I'm not going to let anyone on any network or in any newspaper dictate what we should do as an organization," Rizzo said adamantly. "They're not the general manager of this club. I am."

For his part, Strasburg, the No. 1 overall selection in the 2009 draft out of San Diego State, said he will fight the decision, which has never been conveyed to him by any member of the Nationals staff.

"I said it recently, they'll have to rip the ball out of my hand," Strasburg said Wednesday night, "and I mean it."

Johnson and pitching coach Steve McCatty have been careful with Strasburg, who has logged 105 innings in 18 starts, an average of just under six innings per start. The rhetoric surrounding this decision, however, is sure to continue.

"We'll do it my way," Rizzo said. "I have the full support of ownership on this issue. It's my decision and I've made it. There will be no going back on the decision."