SEATTLE— The Royals continued their struggles against left-handed starters this season during a 7-0 loss to left-hander Mike Montgomery and the Mariners on Tuesday.That makes six straight losses to left-handed starters -- the Royals haven’t beaten one since Chris Capuano of the Yankees at Kauffman Stadium on May 17.The Royals also have lost eight of 12 against left-handed starters on the road and are 10-13 against them overall.But Royals manager Ned Yost said he doesn’t see a trend.“It’s just one of those things,” Yost said. “Not overly concerned. When we’re swinging the bats good, our lefties hit lefties pretty well.