A brawl started when Royals starter Yordano Ventura hit Orioles infielder Manny Machado with a 99-mph fastball.
Machado jawed at Ventura in his previous at-bat, and the right-hander nailed him around the left hip/lower back with the first pitch when Machado came up in the fifth. Machado then threw off his helmet, raced to the mound and fired a hard right that appeared to hit Ventura's face.
"You know, Ventura, in Manny's (earlier) at-bat, was pitching him in," Kansas City manager Ned Yost said. "Obviously, he didn't like it. I don't know who's at fault there."
As a result, Wednesday's game figures to have some extra tension.
"Bring it on," Orioles manager Buck Showalter said. "Bring it on. We'll handle it. You try not to let one person's actions speak for a lot of people but it's been going on for a while with him."
On top of the extracurriculars, the Royals will try to snap their season-high six-game losing streak while the Orioles attempt to a complete a three-game sweep of the defending world champs when the two teams meet on Wednesday night.
The Royals won six in a row and had moved into first place in the American League Central after stumbling earlier in May and slipping below .500.
Kansas City lost five in a row earlier this season and has been inconsistent at times. Yost said he's got a veteran team that's dealt with these situations before.
"It helps a lot to be able to know that you're going to get through it," Yost said. "You've just got to continue to come out ready to play every single day. It helps when you've been through it a number of times, and then have come through it and you've been successful because of it."
The Orioles, meanwhile, have won six of their last seven and three in a row after Boston took the first two games of their four-game series last week.
The Orioles are trying to close their 10-game homestand with a bang. Baltimore bounced back to score 25 runs and win the last two games of the four-game series with Boston.
After that, the Orioles took two of three from the Yankees and the first two games of this series. They'll send top starter Chris Tillman (7-1, 3.33 ERA) to the hill against Kansas City's Edinson Volquez (5-5, 4.03).
Tillman has won six straight decisions but struggled a bit in his last two starts, giving up six homers overall. He'd allowed just three in his first 10 outings.
Volquez also has struggled lately. The right-hander is just 2-5 with a 5.51 ERA in his last eight starts after beginning the season 3-0 with a 1.09 ERA in his first four.
The Orioles might be getting some help for their struggling starting rotation shortly. Yovani Gallardo had a rehab start at Triple-A Norfolk Tuesday and could be in line to make a start on Sunday in Toronto.
Showalter said that the Orioles will make a decision in the next few days.
Injuries are hurting the Royals in recent times. They avoided bigger problems when third baseman Cheslor Cuthbert came back Tuesday after injuring his arm in Monday's game when Baltimore second baseman Jonathan Schoop tried to stop a double play throw but the ball still came out of his hand.
Cuthbert started Tuesday and went 1-for-4.
Yost also said that Alex Gordon (fractured right wrist) has been shagging balls and began his throwing program Monday but there's no date for his return yet.
Kansas City is looking to avoid a second straight series sweep on Wednesday. The six-game losing skid is a season high but there'll be plenty to focus on if anything like Tuesday's brawl happens again, as there's no question the Orioles felt Ventura threw at Machado.
"There's a lot of people that are not in baseball because of the way they act," Orioles starter Ubaldo Jimenez said. "(Ventura) needs some help."