Marty Niland: Five things that must go right for the Nats to succeed in 2015

How can a team that hasn't even competed in a league championship series be a favorite to win the World Series?

It may seem odd, but that's the predicament the Nationals find themselves in as they enter the 2015 season. Experts nationwide have pegged a team with a bullpen full of question marks, Denard Span, Anthony Rendon, Jayson Werth and Casey Janssen on the disabled list, and an 0-for-2 mark in the postseason since moving to Washington 10 years ago as the team to beat.

The expectations are just as high within the clubhouse. When asked what he thought after learning the team had landed prized free agent pitcher Max Scherzer, outfielder Bryce Harper mused, "Where's my ring?"

With all this in mind, could anyone blame the fans at Nationals Park for getting restless if the team doesn't play up to such lofty standards right out of the gate? This club faced similar expectations two years ago after coming within a strike of beating the Cardinals in the 2012 National League Division Series. Instead, they floundered through an injury-riddled 2013 campaign, never threatening the NL East lead and falling short of a wild card spot.

Remember also that this team was 27-28 on June 1 last season before surging to an NL-best 96 victories. Fans might not be so patient this year. Here are five things that need to happen to for the Nats to stay on track for their lofty goals this season.

The rotation needs to come through as advertised: The seeds of the Nats' high expectations were sown when general manager Mike Rizzo signed Scherzer to a seven-year $210 million contract, then announced that he did not intend to trade Jordan Zimmermann, who seems likely to leave the team via free agency after this season. The super rotation of Scherzer, Zimmermann, Stephen Strasburg, Gio Gonzalez and Doug Fister has the potential to put together winning streaks and stop losing skids. But with injuries to key offensive stars, this is not a team that seems unlikely to put a lot of runs on the board. The pitchers will have to be at their best night in and night out, at least until the offensive regulars are healthy again.

The bullpen needs to define its roles and gel quickly: Of all the offseason moves Rizzo made, the one that shocked fans the most might have been the trade of beloved setup man Tyler Clippard to Oakland for infielder Yunel Escobar. With Janssen starting the season on the disabled list, there is no clear-cut setup man for closer Drew Storen, who's on a short leash of his own after failing to hold a ninth-inning lead in the eventual 18-inning playoff loss to San Francisco. We need to find out who from among Tanner Roark, Aaron Barrett and Blake Treinen will fill the setup role while Janssen is out. If Storen falters again, one of them may need to step in to that role, too.

Bench players need to make the most of their opportunities: Center fielder Michael A. Taylor, left fielder Tyler Moore and second baseman Dan Uggla will be filling in while Span, Werth and Rendon are on the disabled list. Span and Rendon may be out for at least a month. Moore has been mostly a bust since getting a few key pinch hits in the Nats' 2012 NL East championship run, and Uggla hasn't been relevant since he had a .348 on-base percentage with the Braves that same season. Taylor was supposed to develop this year before potentially taking over for Span in 2016. They don't all need to put up All-Star numbers for the first month of the season, but if the team has to start searching for other answers at any of their positions in the next month, it's a sign of trouble.

Walk-year players need to earn their money: Ian Desmond, Zimmermann, Fister and Span (after returning to the lineup), this means you. It's a calculated gamble on Rizzo's part to let so many players go into the final year of their contracts without being assured of compensation. But if they can produce the way many players do when they're playing for a big free agent contract, the team won't have to worry so much about the injuries.

Harper needs to step up: It really doesn't matter whether the 22-year-old, fourth-year player deserves his peers' vote as the major leagues' most overrated player two years running. It's time for him to put together a complete season. Harper is a year removed from a major knee injury, hitting third in the lineup and coming off a monster NLDS where he was the team's only consistent offensive performer. With veteran leader Ryan Zimmerman coming off an injury of his own and adjusting to a new position, Harper needs to keep that up and be the potent left-handed bat the lineup desperately needs.

The weight of high expectations has again been thrust on the Nationals shoulders. But as they learned in 2013, nothing will be handed to them. With several key players on the disabled list and others still unsettled on their roles, the key pieces need to fall into place for the team to meet the high goals that have been set.

Marty Niland blogs about the Nationals for D.C. Baseball History. Follow him on Twitter: @martyball98. His thoughts on the Nationals will appear here as part of MASNsports.com's season-long initiative of welcoming guest bloggers to our site. All opinions expressed are those of the guest bloggers, who are not employed by MASNsports.com but are just as passionate about their baseball as our roster of writers.