Time to be worried about the slumping Royals?

The Kansas City Royals have lost eight of their past 10 games and are 4-9 in September. Manager Ned Yost compared this recent run to the flu, which is worse than a cold although not as severe as the plague. The Cleveland Indians beat the Royals 8-3 on Monday as Jason Kipnis and Giovanny Urshela homered off Edinson Volquez. The Indians then broke open a 4-3 lead with three runs off Kelvin Herrera with three runs in the bottom of the seventh.

So the question: Is Yost right? Is this just a few sniffles in the midst of a long season, or is there a reason to be concerned about the Royals? Consider some of the facts:

  • In the first half of the season, the Royals allowed 3.69 runs per game. In the second half, they've allowed 4.44 runs per game. In September, they've allowed 6.62 runs per game.

  • It's not just Johnny Cueto struggling. Herrera has allowed seven runs his past two outings and since the beginning of August has allowed 12 runs in 17 innings, walking nine batters. Volquez has a 5.23 ERA over his past seven starts, allowing six runs in three of those.

  • The bullpen, that invincible bullpen, had a 2.19 ERA in the first half. In the second half, however, it's 3.63. Wade Davis remains as dominant as last season, but closer Greg Holland rested 10 days after an appearance on Aug. 28, pitched on Sep. 8 and 9 and this happened:

  • The offense is less of a concern, scoring 4.62 runs per game in the first compared to 4.42 in the first half, with near-identical OPS figures over the two halves. Alex Gordon returned from the disabled list and in 11 games has hit .375/.400/.525, including a 4-for-5 effort on Monday from the leadoff. The team's September numbers are boosted by three big wins -- 12, 14 and 15 runs scored -- but they've scored two runs or fewer in five of their past 10 games.

  • On the other hand, cleanup hitter Eric Hosmer has now gone 28 games and 100 at-bats without a home run.

  • The bottom three guys in Monday's lineup -- catcher Salvador Perez, right fielder Alex Rios and shortstop Alcides Escobar -- are looking like a pretty soft bottom of the order, with season OBPs under .300. Escobar in particular has struggled in the second half, hitting .206/.243/.240.

All of this focusing on the negative. The Royals still have the best record in the American League. Ben Zobrist has been a terrific addition. Yordano Ventura had been pitching better until walking eight batters his past two starts. The team has already hit 23 more home runs than last year's squad. Kendrys Morales is still driving in runs. And so on.

Should Royals fans be concerned? After all, doesn't everyone always say you want to be playing well heading into the postseason?

I did a quick little study. Since 2010, 46 teams have made the postseason. It's pretty unusual for a playoff teams to have a bad September (includes October games as well): Only seven of the 46 teams finished with a losing record; two finished .500; 37 finished over .500. The average record in September for a playoff-bound team over these past five seasons was 16.7-11.2, a .598 winning percentage. That's compared to an overall .577 winning percentage. So, on average, playoff teams play a little better the final month.

OK, but do teams that finish well do any better in the playoffs?

The nine teams that finished .500 or worse in September went 19-29 in the postseason; none reached the World Series.

The nine best teams in September went 44-42 and three reached the World Series -- the 2011 Cardinals and Rangers and the 2013 Cardinals. However, our 10th hottest team was the 2012 Giants, who went 20-10 September and then 11-5 in winning the World Series. And our 12th hottest team was the 2010 Giants, 19-10 in September and 11-4 in the postseason.

On the other hand, the 10th-worst team was the 2014 Giants, who went 13-12 record in September -- including a 3-8 stretch at one point -- before getting hot in October.

Still, there appears some correlation to playing well the final month of the regular season and doing better in the playoffs. If you're Yost, you're certainly not happy with the recent play and you'd like the team to dial it up soon. In some ways, the Royals remind me of the 2011 Phillies, who went 102-60 but coasted to a 16-14 final month after building a big lead in the division. The Royals also looked like a potential 100-win team before this recent stretch. That Phillies team never seemed to wake from their late-season slumber and lost in the division series to an inferior Cardinals team.

The Royals have 19 games left in the regular season. There's time to exorcise this flu.