"This sport we play works in mysterious ways sometimes," a dejected and visibly upset Romero said. "You can be on top of the world one day and the next day you're trying to find yourself, and that's what I feel like right now. You feel like you're in quicksand, and every time you just keep getting deeper and deeper and you don't know how to get out of it.
"I'm going to continue to stay positive and get through this."
The eight runs pushed Romero's ERA to 5.35. The lefty has allowed at least four runs in 10 of his past 12 starts, and has the second-most walks in the American League with 55.
Romero's struggles are even tougher to swallow in the absence of injured starters Brandon Morrow, Drew Hutchison, and Kyle Drabek.
Romero (8-3) was coming off a career year in 2011 that saw him set personal bests in wins (15), ERA (2.92), strikeouts (178) and innings (225).
"I felt like I was in better control of myself mechanically and I felt good mentally," said Romero, who walked three, struck out four. "I had a good bullpen. It's disappointing to look up there and see those scores. It's one of those things. You go through these rough patches and sometimes you feel like it's never going to end, and that's how I feel right now."
Romero, who sat alone at his locker with a towel over his head and hands in his face before addressing the media, was consoled at one point by teammate Brett Lawrie, who was seen patting him on the back and presumably offering some words of encouragement.
"This team is a really tight group, the stuff he had to say means a lot to me," Romero said. "All you expect from me is I'm going to continue working hard. I'll do whatever it takes to kind of keep getting better and get ready for my next start."
Blue Jays manager John Farrell said Romero's outing was a step in the right direction, despite the outcome. Farrell had spoken all week about the importance of Romero getting ahead in counts with his fastball and throwing it for strikes to his armside.
The skipper thought the lack of walks, at least compared to his last outing where he surrendered six, and overall control is what constituted the step in the right direction. Romero threw more first-pitch strikes, and had better depth to both his changeup and curveball, according to Farrell, but the problem was commanding his fastball within the strike zone.
"I think we've seen Ricky pitch with a greater level of confidence in the past, that's probably not at his highest right now," Farrell said. "A step in the right direction, but still far from what we've been accustomed to seeing from Ricky."
Romero had a 1-0 lead to work with after Toronto scored once in the first inning, but quickly watched it evaporate, starting in the second after Royals catcher Salvador Perez hit a two-run homer to put Kansas City in front, 2-1.
After surrendering two more runs in each of the third and fourth innings, Romero settled down until the seventh.
Before being yanked, Romero issued a leadoff walk to Alcides Escobar and a double to Eric Hosmer -- the third time the Royals first baseman reached base against Romero.
Farrell removed Romero at that point after 104 pitches -- 61 for strikes -- in favor of right-hander David Pauley.
Pauley hit Billy Butler, the first batter he faced, before Yuniesky Betancourt picked up his second RBI of the game with a single to left to give the Royals a 7-3 lead.
The next batter, Mike Moustakas, unloaded on a first-pitch fastball for his first career grand slam to dead center that put Kansas City up by eight.
Pauley, who was designated for assignment following the game, and Romero combined to surrender 14 hits total -- the sixth straight game Toronto pitchers have allowed at least 10 hits.
Toronto had trouble solving Royals starter Everett Teaford. After surrendering a first-inning run, Teaford kept the Blue Jays in check other than solo home runs from Jose Bautista and Colby Rasmus.
Bautista hit his Major League-leading 27th home run, while Rasmus hit his 10th homer since moving into the No. 2 spot in the lineup on June 5, and 16th of the season.
Teaford pitched a career-high seven innings, allowing three runs on five hits, while walking two and striking out a pair to pick up his first win of the year.
The Blue Jays, losers of two straight, fell back to .500 at 40-40.