The Royals have lost eight of their last 11 games, but hope to improve against an American League West opponent that's had similar issues as of late. Seattle's lost seven of its last 10 and hasn't won a series since taking two of three from the Giants on June 15-17.
Kansas City turns to left-hander Jonathan Sanchez, who hasn't exactly been reliable with his performances this season, in the series opener. Sanchez enters the game 1-6 with a 6.75 ERA and hasn't recorded a win since April 8, his first start of 2012.
Despite missing more than a month with left biceps tendinitis, Sanchez is ninth in the AL in walks issued (43). His 7.4 walks per nine innings and 0.79 strikeout-to-walk rate would both rank as the worst in the Majors if he qualified.
The walks have especially plagued the lefty of late. He allowed 20 runs in four games before the All-Star break on 26 hits and 19 walks while striking out 12. However, manager Ned Yost said Sanchez showed promise in his most recent outing against the Tigers.
"His strike-to-ball ratio (60 strikes, 41 balls) was better and his command was better," Yost said after Sanchez allowed four runs on six hits with three walks and two strikeouts in 5 2/3 innings. "He kept us in the game. It was something to build upon."
Sanchez's opponent, Jason Vargas, capped off the first half in a different fashion. Vargas, who is 8-7 with a 4.07 ERA, concluded with his first complete game of the season against Oakland.
"That was just a good, crisp ballgame," manager Eric Wedge said after the win. "Obviously, Jason set the tone."
It was Vargas' team-leading eighth win and snapped a string of five straight starts with either a loss or no-decision.
Royals: Escobar fitting nicely in two-hole
Alcides Escobar moved into the No. 2 spot in the Royals lineup on July 1 and hasn't looked back. In his past 11 games, Escobar is batting .311 with two doubles, a triple, two home runs and seven RBIs.
"He's done so good, and you look at him and you can really envision him being a No. 2 hitter on a championship club," Yost said. "He's doing everything we want him to do in the two-spot."
Escobar concluded the three-game series against the White Sox on Sunday with another two-hit game -- his third straight and sixth in July. He batted .462 (6-for-13) with a triple, two home runs and six RBIs in the three games.
Mariners: Smoak still struggling
It's been a season to forget for first baseman Justin Smoak. The 25-year-old, who was the No. 11 pick in the 2008 First-Year Player Draft, went 0-for-4 on Sunday to drop his batting average to .199 on the season.
"I feel like we've had a lot of conversations with him," Wedge said. "I don't think he's that far along, but I feel he's not too far away."
More than half of the Mariners' games have been decided by one or two runs (45 of 89). They are 10-16 in one-run games and 7-12 in two-run games. They've played the second-most games decided by two runs or fewer in the AL with the Tigers having the most (49).
The Mariners celebrated the 13th birthday of Safeco Field on Sunday, as they concluded a three-game series with the Rangers. The park opened on July 15, 1999, and the Rangers were the final visiting team to play at Seattle's former home stadium, the Kingdome.
Vargas is 2-1 with a 4.26 ERA vs. Kansas City in three career starts. For Sanchez, it will mark the first start of his career against Seattle, however, he's pitched one scoreless inning of relief, allowing a walk.