Should the Royals be worried about their bullpen?

Sunday's matchup between the Los Angeles Angels and Kansas City Royals was great. It was also a frightening game for two teams some have already painted into the postseason picture. After they lost three of four in Kansas City and six of their past seven games, the Angels have tumbled to just a half-game ahead of the Rangers for second in the AL West. For the Royals, even while they celebrate their walk-off win thanks to Kendrys Morales' single in the 10th inning, they have a major question where they once thought themselves strong: the bullpen.

The Angels might reasonably grumble over a game lost because Huston Street was squeezed by home-plate ump Quinn Wolcott, and they might thank Mike Trout for getting the game into extras with his game-saving catch. But the Angels are just asking for trouble with an offense that has collapsed in August, with just 2.6 runs per game this month. You can credit the front office for trying to shore up the lineup, but the additions of David DeJesus, Shane Victorino, Conor Gillaspie and David Murphy haven’t added much punch. If this continues, you can wonder if the Angels are finished dealing. Clearly, they need help.

In contrast, you might think the Royals are made of good news. They're 19-12 since the break. They added Johnny Cueto and Ben Zobrist at the trade deadline, and both look great. Yordano Ventura threw his second straight sweet start and third in five games Sunday after a one-day demotion to Omaha had to be chucked due to Jason Vargas' season-ending injury. The switch-hitting Morales has been a godsend at DH, producing an .806 OPS with 46 extra-base hits while slugging .490 from the left side of the plate.

But if the bullpen doesn’t iron out its issues down the stretch, the Royals’ run into October might not go the distance. Perhaps the past year and a half spoiled fans. Maybe we started taking the Royals’ late-game threesome for granted. That's forgivable. Kelvin Herrera, Wade Davis and Greg Holland were crucial to last season’s pennant, and they seemed the most dominant power trio this side of Motorhead (sorry, fans of Nirvana or Cream) -- until the All-Star break, that is.

Nobody had homered against Davis since Ian Desmond on Aug. 24, 2013. That's a stretch of 477 batters that was busted Aug. 1 by Jose Bautista off a 97 mph fastball. Davis' latest homerless streak lasted just 13 batters and ended with Kole Calhoun jacking a hanging curve over the right-field fence in the top of the eighth inning Sunday. Davis is working his way through back problems, and the Royals have tried to keep him out of action to help him heal, but if he’s leaving his pitches up and in the zone, it could be the start of an ugly trend.

Holland also hasn’t looked good. He has blown two of nine save opportunities while allowing 22 baserunners in 10 innings. He blew a save Aug. 13, when the Royals lost a game they led after eight since innings for the first time since May 5, 2014. One key issue has been Holland's fastball dropping from around 96.5 mph to around 94.5, and though it has come back up a tick in August, he’s struggling with location. As for Herrera, since the break, he has blown three of the six leads with which he was entrusted, and his strikeout rate has dropped to just six per nine innings, which is less than overpowering.

The performance problems of these three aren’t crippling across the span of a six-month season. This could just be a rough month from a great unit. There is time for each to turn things back around. There is certainly an element of irony in seeing what had been the Royals' greatest strength break down at a time when their rotation and lineup look good for the stretch run. But for the Royals’ sake, for all they have at stake, they better hope Herrera, Davis and Holland get back on track sooner rather than later.

Christina Kahrl writes about MLB for ESPN. You can follow her on Twitter.