A.J. Cole posted a 3.81 ERA with the Nationals in 2017. (Matt Slocum/AP)

Starting pitching has been the backbone of the Washington Nationals’ success over the past six seasons. Since 2012, the Nationals have not ranked below seventh in baseball in starters’ ERA. Max Scherzer, their ace, is the two-time-defending National League Cy Young Award winner. Stephen Strasburg, their No. 2 starter, finished third in the Cy Young voting this year and was arguably the best pitcher in baseball for the final two months of the 2017 campaign. With those two all-stars plus Gio Gonzalez and Tanner Roark behind them, Washington believes its rotation is up there with any other in baseball.

But starting rotations go five-deep (and, in some cases, six-deep) nowadays, and Washington has a hole in the fifth spot. Joe Ross was supposed to fill the vacancy in 2018, but he underwent Tommy John surgery last July and is expected to miss at least half of next season. That leaves the Nationals in search of a No. 5 starter to assume the role at least until Ross returns.

Washington may not have to look far. A.J. Cole, once a prized prospect whose shine wore off over the previous two seasons, impressed Nationals decision-makers when given the opportunity in 2017. While the Nationals were running away with the National League East with little at stake, Cole posted a 3.00 ERA in his final eight appearances (five starts) across 36 innings down the stretch. He finished the season with a 3.81 ERA in 52 innings in the majors — after pitching to a ghastly 5.88 ERA in 18 starts with Class AAA Syracuse.

Cole’s stuff was better (his fastball velocity jumped from 91.8 mph in 2016 to 93.2 mph), but he averaged just 7.6 strikeouts per nine innings and his 5.20 FIP suggests he benefited from plenty of luck. Regardless, the strong conclusion placed him in contention for the No. 5 spot next season alongside fellow internal candidate and top pitching prospect Erick Fedde. One other factor boosting Cole’s case: He is out of options, which means the Nationals would have to expose him to waivers if he doesn’t make the Opening Day roster.

Of course, plenty can happen before the Nationals report for spring training in mid-February. The Nationals most certainly will acquire starting pitchers to address their lack of depth — Austin Voth is the only other starting pitcher on their 40-man roster who has started a game above Class A, and he had a 5.94 ERA between three minor league levels in 2017 — and they would presumably compete for the vacancy. They could also acquire a top-of-the-rotation type to slide in behind Scherzer and Strasburg, and push Gonzalez, who is entering the final year of his contract, and Roark to the back end. Remember, the Nationals tried to do that a year ago, but their pursuit of Chris Sale fell short.

The Sale chase reached its apex at the Winter Meetings at National Harbor before the Boston Red Sox swooped in and acquired the lefty. This year’s Winter Meetings begin Sunday in Orlando. A flurry of activity is expected across the sport after a month of very little action. For now, Cole is in contention for the No. 5 spot.

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