From April of 2012 to late Friday afternoon, the Washington Nationals could pretty much always count on Gio Gonzalez taking his turn in the starting rotation. In his first six seasons with the team, he made 30 or more starts in all but one of them. He made 27 for the Nationals so far this season, his durable left arm — though less effective in recent months — a staple of the franchise’s rise to annual contention in the last half-decade.

Then he was traded to the Milwaukee Brewers on Friday, another trade of the Nationals’ August sell-off, and his spot in the rotation has to finally be filled.

Before the Nationals traded Gonzalez, on the final day a player could join a team and be eligible to play for that club in the postseason, they parted with reliever Ryan Madson (earlier on Friday), Daniel Murphy and Matt Adams (on Aug. 22), and relievers Brandon Kintzler and Shawn Kelley (at the non-waiver trade deadline on July 31). That means the Gonzalez deal is the first to directly affect the team’s starting rotation, even if the 32-year-old veteran has been spotty, at best, since a strong start to the year.

Over his seven seasons with the Nationals, Gonzalez compiled an 85-65 record with a 3.62 ERA. But he has not padded those statistics in the past three months. Since starting this season 6-2, Gonzalez is 1-9 with a 6.53 ERA and will look to find some semblance of consistency with the Brewers, who are in the thick of the National League wild-card race. The Nationals, on the other hand, are slipping farther out of the playoff hunt following a 4-1 loss to the Brewers at home on Friday night.

Life after Kinztler and Kelly and Murphy and Adams continues to be unkind to the Nationals. How they handle life after Gio Gonzalez will soon become more clear.

“We know we’ve got [Erick] Fedde coming back, and Joe Ross will be back here soon,” Nationals Manager Dave Martinez said after Friday’s loss. “We’re going to sit down tonight and figure out who’s going to fit in that spot the next time around.”

Gonzalez’s last start for the Nationals came on Wednesday — an 8-6 loss to the Phillies in Philadelphia — so he would have been expected to pitch next against the St. Louis Cardinals on Tuesday. The Nationals could fill that spot in a lot of ways, and their list of potential options includes Ross, Fedde, Jeremy Hellickson, Tommy Millone or a minor league pitcher such as Austin Voth, Kyle McGowin or Austen Williams.

Ross, a proven back-of-the-rotation starter, has missed all of this season while recovering from Tommy John surgery. Fedde, the team’s top-rated pitching prospect coming into this year, has been on the disabled list since June with a shoulder injury, and was in the rotation (in place of then-injured Stephen Strasburg) when the pain began in a start against the Boston Red Sox. Both Ross and Fedde have made multiple minor-league rehab starts and could be nearing a return. Martinez said during the week that he could see Ross joining the Nationals after Sept. 3, when the team plans to expand its roster with a handful of September call-ups.

Hellickson and Millone each went to the 10-day DL in August: Hellickson with a right wrist sprain and Millone with shoulder soreness in his throwing arm. Hellickson threw a 30-pitch bullpen in Philadelphia on Wednesday and said he felt good afterward, but is still not using his curveball because it shoots pain into his wrist. He seems most likely to round out the Nationals’ rotation once he is ready to return. Millone, who was moved to the bullpen before he went to the DL, has made four starts for the Nationals this season and has been inactive since Aug. 21. Millone will throw a rehab start with the Class AA Harrisburg Senators in Richmond on Saturday, and Martinez said the Nationals will see how that goes before assessing his short-term availability.

A spot starter, like Voth or McGowin or Williams, could be available with the minor league season ending Monday. The Nationals would need to make room for any one of those pitchers on their 40-man roster, but a spot does open up with Gonzalez’s departure.

Voth is 5-8 with a 4.46 ERA for the Class AAA Syracuse Chiefs this season. He also struggled in his first and only major league start against the New York Mets on July 14, giving up seven runs on nine hits in just 4.1 innings of work. McGowin has made seven starts for the Chiefs since he was called up from Class AA Harrisburg, and is 2-2 with a 1.32 ERA in Syracuse. Williams has made 32 total appearances between Class AA and Class AAA this season, but has only come out of the bullpen in Syracuse. Either way, he has a 1.19 ERA in 68 innings across the two levels and that could possibly earn him a major league call-up for September.

However the Nationals plan to replace Gonzalez in the rotation, there will be a ripple effect that gives more than one pitcher a chance to prove himself.

“It sucks to see guys leave, guys that you’ve played with and got to know, but it’s part of the game,” Nationals starter Tanner Roark said Friday night of Gonzalez’s departure. “Just going to have to go out there and play your game, and now it’s more opportunity for guys to come up here and get their feet wet and learn from being out there on the mound.”

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