But more recent history suggests the loss of Strasburg was not the rotation's only pierced piece of armor. Since the beginning of August, Jordan Zimmermann has not resembled the dominant pitcher he was earlier this season.
After Zimmermann gave up five runs over three innings in Game 2 of the National League Division Series on Monday, in the Nationals' 12-4 loss to the Cardinals at Busch Stadium, few would blame the Nats for wondering how equipped Zimmermann is to rediscover his ace form in October.
"That's some of the youth in the pitching staff," manager Davey Johnson said of Zimmermann's Monday performance. "He didn't really make a lot of adjustments out there."
Though Zimmermann looked sharp in retiring the Cardinals in order in the first inning, he gave up four consecutive hits -- including David Freese's RBI double and Daniel Descalso's run-scoring single -- to open the second. By the time that rally was complete, the Cards had scored four runs off Zimmermann, effectively ensuring that he would not stick around long.
"Against Zimmermann, that's big for us," said St. Louis outfielder Jon Jay, who capped that rally with a key two-out RBI single. "We know what type of offense we have when we are going out there and grinding and having good at-bats, and we did that today. When we do that, we've been tough on starters, and it doesn't matter who is pitching."
Through two games, the Nationals have received a total of eight innings (with seven earned runs allowed) out of their starting pitchers.
"The last two starts," Zimmermann said, "have not been good for us."
Perhaps worse is that should the Nats rebound from Monday's loss to advance past this series, they have no way of knowing which Zimmermann will show up to the NL Championship Series.
On Aug. 19, Zimmermann held the best ERA (2.38) in the Major Leagues, with nine victories and more than four times as many strikeouts as walks. If Strasburg was Washington's ace, Zimmermann was not far behind.
From Aug. 20 until the end of the regular season, however, Zimmermann posted a 4.84 ERA and saw a significant spike in his walk rate, with the league managing an .823 OPS against him. One three-start stretch in late August and early September exacerbated those numbers, when Zimmermann gave up 15 runs over 13 2/3 innings. That he rebounded to finish the regular season relatively strong did give the Nationals hope that he might rediscover his old form in October.
But now this.
It is worth noting, given the organization's caution with Strasburg, that Zimmermann long ago blew by his career-high innings total. In his age-26 season, Zimmermann has already pitched 198 2/3 innings, or 37 1/3 more than his previous high, set last year.
Most modern front offices discount innings spikes for pitchers over 25 years old. But Zimmermann opened this season as a 25-year-old, less than three years removed from his own Tommy John surgery, and has already dealt with a sizable innings increase. Combine those red flags with his recent performance, and there may be reason for concern.
In shutting down Strasburg, the Nats hoped that both Zimmermann and Gio Gonzalez would pitch like aces, weathering the loss of Washington's real No. 1. But if Zimmermann struggles -- or worse, both Zimmermann and Gonzalez struggle -- it could make for a short playoff run.
If the two hurlers rebound, it could make for a long one.
"They've pitched great all year long," Nationals shortstop Ian Desmond said. "They've had their bad starts throughout the year. I guess if that's as bad as they can do, the upside looks really good."