The Royals have had a healthy lead atop the AL Central standings for the last few months and appear destined to win their first division crown since 1985, but the struggles of Johnny Cueto and the rest of the rotation could make the celebration short-lived.

Last season, Kansas City was the feel-good surprise team, finishing with an 89-71 record and clinching its first playoff berth in 29 years. The Royals then defeated the Athletics in the Wild Card Game before sweeping the Angels (3-0) and Orioles (4-0) en route to their first World Series appearance since winning it all in that magical 1985 season.

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When Kansas City entered 2015, most pundits treated the magic of 2014 like a fluke and doubted the club would have the juice to replicate that success. The Royals not only proved their doubters wrong, but, entering play Tuesday, they are already five victories away from eclipsing last season's win total and have a nine-game lead over the Twins atop the AL Central with a magic number of 11 to clinch.

It seemed as though the Royals would be unstoppable when they added a true ace in Cueto in a deal with the Reds prior to the non-waiver deadline in July, but despite the club once again being a feel-good story, the struggles for the right-hander and the rest of the rotation are mounting at the worst possible time.

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Cueto, 29, is 2-6 with the Royals in nine games (56 1/3 innings) with a grisly 5.43 ERA, 41 strikeouts and eight walks. In his last outing, Cueto got smacked around by Baltimore on Sunday, yielding eight runs (seven earned) on 11 hits in 6 1/3 innings.

Cueto is part of a Royals rotation that isn't looking sharp heading into the playoffs. Kansas City's pitching staff has the second-worst ERA in the league in September with a 6.46 mark, falling behind every team but the lowly Athletics (6.51).

The 2014 All-Star isn't the only factor in this issue for the Royals as Yordano Ventura (11-8, 4.42 ERA in 2015) and Edinson Volquez (13-8, 3.59) have both had their share of struggles atop the rotation. Ventura also has a 5.13 ERA away from Kauffman Stadium this season, while Volquez owns an unsavory 7.20 ERA through two starts this month.

Kris Medlen (3-1, 4.58 ERA) will compete for a postseason rotation spot, but he also missed 17 months due to elbow surgery, while Danny Duffy has had problems getting deep into games (one quality start in his last five outings), and is 7-7 with a 4.14 ERA this season.

It's understandable why the Royals added Cueto, but his transition into the American League hasn't gone smoothly. The struggles may not warrant him being left off of the postseason rotation, but he also can't be relied on as the go-to pitcher in a huge game. The righty has three starts to try to turn things around, but Kansas City has some serious questions heading into October.

Cueto, Ventura and Volquez are likely to be the top three starters when the postseason begins, but the former Reds ace could find himself in a race with Duffy and Medlen for two playoff spots. Though Duffy and Medlen have had problems with getting deep into starts, with the Royals bullpen ranking third in the majors with a 2.75 ERA, it may not stop Ned Yost from turning to them.

It's been a fun season in Kansas City, but if it wants to relive the magic of last autumn, the starting rotation is going to have to right the ship.

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