KANSAS CITY -- When key members of a starting rotation are injured, it can cause big problems. And when the remaining guys who are asked to at least temporarily fill the breach don’t come through with lengthy outings, those problems can quickly compound.

The Astros find themselves with that predicament as they head home after an early knockdown Thursday doomed them in a 13-3 loss to the Royals. Against right-hander Hunter Brown, the Royals put on a wild offensive show in the opening inning that finished Brown's day after just two-thirds of an inning. Brown allowed 11 hits and nine runs before manager Joe Espada called on Seth Martinez to get the final out in the first.

One night earlier, the Royals tagged rookie right-hander Spencer Arrighetti for six hits and seven runs in the third inning. But that robust rally paled in comparison to what happened on Thursday in the first as the Royals sent 15 batters to the plate, one shy of a club record.

Brown also had a rough time in his previous outing April 5 against Texas, when he allowed eight hits and five runs over just three innings. In three of their last four games, the Astros’ starters have gone three innings or less, which has put considerable stress on the bullpen. Third baseman Grae Kessinger wound up pitching a 1-2-3 eighth inning in Thursday's blowout.

Simply put -- with headliners such as Justin Verlander and Framber Valdez sidelined, the Astros need others to step up. By having to use his bullpen early and often, Espada is concerned that the wear and tear could become problematic.

“It’s something I think about all the time,” Espada said. “Keeping those [bullpen] guys healthy is important for us to accomplish our goal. But at some point, we’re going to get the starters to do their job. They will. They’ve done it in the past. It’s just a matter of time.”

Brown largely attributed Kansas City’s consistently hard contact without much swing-and-miss to the fact that he was leaving pitches over the middle of the plate. But Brown also said he will do some film study to determine whether he might have been tipping pitches.

“Yeah, I’m going to have to check the film,” Brown said. “For the most part, I was pretty general over the middle of the dish. So, tough to say. I’m definitely not happy about it. I have to look into it deeper. I have to sit down with the staff and see what I can do.”

Espada could conceivably get Verlander back in the near future to ease the starting pitching burden, but Espada emphasized that the club wants Verlander to have one more rehab outing this weekend before that could happen.

"We’re doing the best for JV and our team,” Espada said. “JV gets another Minor League rehab. When he’s ready, we’ll be ready to welcome him in.”

After being swept by the Royals, Houston headed home 4-10 and will look to gain some traction this weekend against the Rangers.

Pitching isn’t the only problem, as the offense was unable to generate more than three runs in any of the Kansas City games.

“We’ve been tested early,” Espada said. “This team has been tested before. This is going to make us better. It’s hard to swallow, but I have faith in that group in there. We’ll figure it out.”