Each day this week, we’ll be taking stock of every Nationals positional group. In Part 1 of 5 today, we’ll analyze the starting rotation.

Season review

The Nationals returned their stellar core trio of Stephen Strasburg, Jordan Zimmermann and Gio Gonzalez. After two years of cycling through No. 4 and 5 starters – Chien-Ming Wang, Ross Detwiler, Edwin Jackson, Dan Haren, Taylor Jordan – they found two stalwarts in sudden star Tanner Roark and trade acquisition Doug Fister.

The result gave the Nationals perhaps the best starting pitching in the major leagues. They led the majors with a 3.04 ERA, ranked second with a 4.05 strikeout-to-walk rate and 17.6 wins above replacement and finished fifth with 1,002 1/3 innings. The 2014 Nationals were strong across the board, but their strongest piece was their rotation.

Strasburg surpassed 200 innings for the first time in his career, producing one of the best extended stretches of his career at the end of the regular season before making a lukewarm playoff start. Jordan Zimmermann made his second all-star team, punched up a career-best 2.68 ERA and struck out 8.2 hitters per nine innings, an increase of 1.4 over 2013. He solidified himself as one of the best right-handers in baseball.

Roark emerged as a reliable, often excellent back-of-the-rotation starter who posted a 2.85 ERA over 198 2/3 innings and, best of all for the Nationals, will make the league minimum for another two years. Fister was an absolute steal from the Tigers, going 16-6 with a team-best 2.41 ERA after missing the season’s first month with a lat strain. He also dominated in the Nationals’ only postseason victory. Gonzalez landed on the disabled list for the first time in his career after struggling through shoulder tightness, but by the end of the season had returned to form – and then fumbled away NLDS Game 4 with two costly defensive miscues.

Jordan began the season in the rotation before decreased velocity and subpar results got him sent to Class AAA Syracuse. Jordan, who recovered from Tommy John surgery in 2012, ended the season on the disabled list with a vague elbow injury that the Nationals claimed did not portend another ligament-replacement procedure. While his star dimmed, the Nationals received promising work from hard-throwing sinkerballer Blake Treinen, who posted a 2.49 in 50 2/3 innings in spot-start and long-relief duty.

Offseason outlook

The biggest decision facing the Nationals is whether they can sign Zimmermann and/or Fister to contract extensions that will take them beyond the 2015 season, when both will be eligible for free agency.

The Nationals engaged with both about long-term extensions last season. The Nationals reached a two-year, $24 million deal with Zimmermann, $16.5 million of which he’ll make in 2015. They shared dialogue about a longer deal, but the talks stalled. The Reds did the Nationals no favors when they signed Homer Bailey to a five-year, $105 million extension. Given that deal and Zimmermann’s excellence this season, any contract Zimmermann signs will likely be the largest the Nationals have ever given, possibly approaching the six-year, $144 million deal Cole Hamels signed in 2013.

Fister, who owns a career 3.34 ERA in nearly 1,000 innings, would not command the same nose-bleed salary as Zimmermann, but an extension for him would look similar to Bailey’s, if not surpass it.

If the Nationals cannot come to a long-term agreement with either, they would have to at least consider trading one or both, lest they risk watching a valuable asset sign elsewhere in a year with only a compensatory draft choice in return.

The more reasonable assumption is that both will return, either for the start of a long deal or the end of their Nationals’ tenure. Roark is a low-cost lock to return. Gonzalez’s deal, which has become a sweetheart contract for the Nationals, calls for him to make $11 million in 2015. Strasburg will receive a nice bump from the $3.98 million he made last year through arbitration, but he remains affordable, especially in relation to his ability and production.

Possible free agent targets

In the likeliest outcome, the Nationals will not need to shop for free agents. Beyond the five returning starters, they have Treinen, Jordan, Taylor Hill and A.J. Cole as potential depth in the minor leagues. Chris Young, whom the Nationals have signed to a minor league deal two straight springs, would be available again, too.

In the less likely event the Nationals trade Zimmermann or Fister, veterans Jake Peavy, Jason Hammel and Ryan Vogelsong may make sense as cheaper, short-term options as the Nationals wait for their young starting pitching prospects to mature. Given the depth they’ve built, though, the Nationals are unlikely to add starting pitching via the free agent market.

Prospect to watch

Lucas Giolito remains not only the Nationals’ best prospect, but also one of the best pitching prospects in the major leagues. Reynaldo Lopez emerged late last season as another promising arm who could skyrocket up prospect lists. But right-hander A.J. Cole may be ready to contribute this season.

Cole, who turns 23 in January, could slide into the top 50 of major prospect lists this spring after he went 13-3 with a 3.16 ERA over 134 innings between Class AA and Class AAA this season. Cole struck out 50 and walked 17 in 61 innings at Class AAA Syracuse to end the season. The Nationals need to add him to their 40-man roster this winter to protect him from the Rule 5 draft, and so he’ll have a clear path to the majors.

The Nationals drafted Cole in the fourth round of the 2010 drafted and gave him a $2 million signing bonus. They traded him in December 2011 to the Oakland A’s as part of the package that acquired Gio Gonzalez. The Nationals re-acquired Cole – along with lefty reliever Ian Krol and Treinen – in January 2013 in trade when they sent Michael Morse to Seattle in a three-team trade. After a winding path, Cole may be ready to make a big league impact.