One year ago Thursday, Nationals President of Baseball Operations Mike Rizzo helped Max Scherzer put on a Nationals jersey for the first time. Jordan Zimmermann, Stephen Strasburg, Gio Gonzalez, and Doug Fister had long since been fitted for theirs, so the deepest starting rotation in baseball coalesced in white and red. That rotation was so deep that a 15-game winner suddenly constituted a contingency plan, so deep that prospects who nearly had elbowed into rotation spots a year before were suddenly boxed out of the major league roster.

As it happened, that rotation wasn’t deep enough to win the World Series. That rotation was not deep enough to win the National League East. Now, Jordan Zimmermann and Doug Fister are gone, and the Nationals seem content to replace them internally. Tanner Roark, the 2014 15-game winner left out last season, will slide back in. Joe Ross, plucked from Class AA when injuries struck, likely will be given a full-season chance. This year’s rotation will not be as deep as last year’s. So what exactly will it be?

Let’s begin with what may be an unreasonable scenario: one in which every starter stays relatively healthy for the entire season — maybe a missed start here or there, but no disabled-list stints.

One could argue that Scherzer and Strasburg, when healthy, comprise the most dominant top-of-the-rotation duo in the majors, particularly now that Clayton Kershaw and Zack Greinke are in separate dugouts. Just four pitchers in the majors have averaged more than 10 strikeouts per nine innings over the past five seasons. Scherzer and Strasburg are the only teammates in that quartet.

Scherzer has been as durable as any starter in baseball during that span. He has made at least 30 starts in each of the past seven seasons, and averaged more than 6 1/3 innings per start since becoming a full-time starter in 2011. Scherzer was named an all-star every season since 2013, and only Clayton Kershaw has thrown more innings since. Even with the kind of rough patch he hit last August, Scherzer could be expected to make 30-plus starts, throw 200-plus innings, and strike out more than 240 batters next season.

Strasburg averaged nearly 29 starts per season and nearly six innings per start since 2012, even though two disabled list stints truncated his 2015 season. If he pitches the way he did in September through 30-plus starts next season, he could push for a second league strikeout title.

Behind that pair sits Gonzalez, whose flighty command often eclipses what has been fairly reliable effectiveness. Over the past five seasons, Gonzalez held batters to a .229 batting average. Just four lefties in baseball have stymied opponents more effectively: Kershaw, Chris Sale, Francisco Lirano, and Madison Bumgarner. Just two left-handed starters maintained a higher strikeouts-per-nine innings ratio than Gonzalez has since 2011: Kershaw and Liriano.

Gonzalez also has been durable, if not always able to pitch late into games. He has made 30 or more starts in every season but one since 2010, though he has averaged fewer than six innings per start in that time. With Zimmermann gone, Gonzalez will assume greater importance. When the Nationals face the Mets, he’ll probably match up with one of New York’s big three. When the Nationals face teams such as the Cubs, Cardinals, and Giants, he’ll oppose an ace-type.

If age yields more consistent command — and it hasn’t yet — Gonzalez has shown the stuff to match up favorably. Should he continue to induce more ground balls, like he did last season, his pitch count could drop if he eliminates fits of nibbling. Either way, he can probably be counted on for 30-plus starts, 10-ish wins, and around 180 innings of work.

Then, the unpredictables. Roark’s 2015 performance has few predictive powers, jostled between the bullpen and starting roles as he was all season. When he started consistently, given time to command all of his pitches and more margin for error than a few bullpen appearances here and there, Roark averaged more than six innings per start and fewer than two walks per nine innings. He did not blow away anyone, but used a good mix of pitches to get contact and quick outs, chugging through enough innings that he earned decisions in 25 of his 31 starts.

Last season, Roark admitted he sometimes found himself trying to throw too hard and aim too precisely, and was therefore overthrowing. Rizzo and new Nationals pitching coach Mike Maddux have indicated a rotation spot is Roark’s to lose this season, and whether he wins 10-plus games again or gives up that spot will tell how much last year’s back-and-forth truly affected his ability to perform.

Then, there’s Ross, the precocious righty who pitched with poise in the big leagues despite having never thrown a game above Class AA. No pitcher in baseball history turned in a higher strikeout-to-walk ratio, 11.8-to-1, over his first seven starts than Ross, Elias said, numbers that helped him nudge Fister out of the rotation.

The Nationals shut down Ross in September. He had thrown more than 150 innings between the minors and the majors, more than ever before in his career. After the season, he admitted hitting the wall most young pitchers encounter during a season in which their innings count rises dramatically. The Nationals have not identified any limits on Ross in 2016, though they will almost certainly be careful. Normally, innings jumps of more than 30 percent are considered dangerous for young arms, so 200 innings might be too much to expect from the 22-year-old. Perhaps 180 is more realistic.

In terms of performance, Ross’s only substantial struggles came when he dealt poorly with humidity in St. Louis, then when he felt fatigue down the stretch. He showed no tendency for nervousness, and will be tested most by his ability to adjust to hitters who have faced him before. Will the devastating slider and improving change-up be enough? If so, the Nationals can expect a quick-working, relatively efficient youngster who won’t back down.

But a mounting workload for Ross down the stretch could require the same kind of depth an injury could. Should one or more Nationals falter, the team likely will have to turn to the same pitchers they relied on in 2015. A.J. Cole struggled in his first outing, then struggled to find consistency in the minors, too. Rizzo admitted he may have rushed his one-time top-10 prospect. Other options include Taylor Jordan and Taylor Hill, neither of whom has been particularly impressive in the majors, both of whom likely will be in Class AAA Syracuse waiting for a call.

Then, of course, there is Lucas Giolito, the top right-handed pitching prospect in baseball according to all the reputable sources. If injuries require the Nationals to reach as deep into the minor leagues as they did last season, perhaps Giolito would be a more intriguing solution than Jordan, Hill, and the rest.

Next year’s starting pitching free agent market is headlined by Strasburg, so elite options at the trade deadline may not be available. More likely, the Nationals would have to look to a lesser name, more of a middle-of-the-rotation type if they feel the need to bolster. Despite the injuries, last year’s rotation accumulated the fourth-best FIP (Fielding Independent Pitching) in the majors. This year’s, as currently contructed, has plenty of talent, but a smaller margin for error.