Updated

KANSAS CITY, Mo. -- The Cleveland Indians open a three-game series with the defending World Series champion Kansas City Royals on Monday, but without starting catcher Yan Gomes.

While the Indians arrived in Kansas City, Gomes was headed back to Cleveland to have his right shoulder checked by Dr. Mark Schickendantz.

Gomes hurt the shoulder Sunday in the fifth inning of a 6-1 victory at Minnesota when he stepped awkwardly on the first base bag while attempting to avoid the tag of Kenny Vargas.

Gomes fell on his right shoulder as he stumbled to the ground while running at full speed and had to be carted off the field.

"As far as I know it is kind of like a shoulder separation," Gomes told Cleveland media after the game. "I'm going to Cleveland to be checked out and we will know more later."

Indians manager Terry Francona said Gomes, who has started 63 games behind the plate, would be placed on the disabled list Monday. He said in all likelihood the Indians would activate catcher Roberto Perez, who had right thumb surgery in May. He has caught nine innings in a minor league rehab assignment.

"Things like this happen," Francona said. "Hopefully, you are prepared so it doesn't get in the way of what you're trying to do."

What the Indians are trying to do is win the American League Central. They hold a commanding 6 1/2-game lead over the Detroit Tigers, who beat the Royals 4-2 Sunday with a walk-off home run. They have an eight-game bulge over the Royals, who are just a game above .500. The Indians have lost seven of 12 since a 14-game winning streak catapulted them into control of the division.

The Indians will receive no sympathy from the Royals on the Gomes' injury. Royals third baseman Mike Moustakas is out for the season after knee surgery and Lorenzo Cain is on the disabled list with a hamstring injury. Cain, however, could begin a minor league rehab assignment this week, but he won't return to the Royals in time to play in the Indians series.

Alex Gordon, who missed 30 games with a wrist fracture, continues to struggle at the plate, hitting .207 with a puny .652 OPS.

"All I can say is, I've played like crap," Gordon told the Kansas City Star.

The Royals will need Gordon to turn it around quickly if they are to make it to postseason for the third straight year.

"We're going to need to get him going, that's for sure," Royals manager Ned Yost said. "He's going to be key."

Corey Kluber, who is 9-8 with a 3.61 ERA, will start the series opener for the Indians. He threw six scoreless innings to beat the Royals in June at Progressive Field, but 10 days later he permitted eight runs, including three unearned, over five innings in a loss at Kauffman Stadium.

Royals first baseman Eric Hosmer is 12-for-45 (.267), with three home runs and 13 RBIs off Kluber. Gordon has a .188 average, 6-for-32, but two of his hits are home runs.

Edinson Volquez, who is 8-8 with a 4.85 ERA, will be the Royals starter Monday. In 11 Volquez starts that theRoyals won, he has a 2.18 ERA while holding opposing hitters to a .225 batting average. In his eight losses, Volquez has a 9.44 ERA with opponents hitting .322.

Indians right fielder Lonnie Chisenhall has 14 hits and a .429 batting average against Volquez, while designated hitter Carlos Santana has a .167 average off the Royals right-hander he has two home runs.

The Indians have defeated the Royals six times in 10 meetings this season, but are 0-3 at Kauffman Stadium.