I don't have to tell you much about Johnny Cueto, not after 23 career starts against the Cubs (143 innings, 3.34 ERA, 1.210 WHIP, marks very close to his career norms).
Early in the 2015 season, Cueto was mentioned as a free agent almost in the same breath as David Price, Zack Greinke and Jordan Zimmermann. He was coming off an excellent 2014 and seemed on his way to another fine year in 2015, with similar numbers.
Then he was traded to the Royals and was awful, and I mean Jeff Samardzija-awful for a while. He had a five-start run from late August to mid-September where he posted a 9.57 ERA and 1.975 WHIP and allowed eight home runs in 26⅓ innings. He redeemed himself somewhat in his final five regular-season starts (3.24 ERA), but then stunk it out twice in the postseason... but also had two really good outings during the playoffs including a complete-game two-hitter in Game 2 of the World Series.
So which is the real Cueto? Is he injured? That's a possible explanation for the bad outings, but there haven't been any reports of injury. He's had injury issues before and missed big chunks of the 2011 and 2013 seasons as a result. Here's a guy who's really good when he's on, but when he's not... man, you don't want that, right?
Cueto's asking price might have come down due to some of those poor performances. He won't require draft compensation since he was traded mid-season. He's certainly familiar with N.L. Central opponents and in particular, dominates the Pirates (18-4, 2.13 ERA in 28 career starts).
Worth looking into? He turns 30 next February. Your thoughts welcome.