DETROIT — Losing a home series to the only team beneath you in the Central Division standings seems like a rough way to spend a holiday weekend. But, given how things have gone this season for the Tigers, it was fitting. The Kansas City Royals rode a pair of second-inning home runs off starter Tarik Skubal to a 7-4 win over the Tigers in the series finale at Comerica Park Sunday. The Tigers’ concern level for Skubal at this point must be high. This was his fifth rocky start in a row, the second straight and third out of his last four that he didn’t get through five innings. After he pitched a …