Preview the Sept. 18 matchup between the Seattle Mariners and Kansas City Royals with odds over/under, game spread, betting lines and more.

Luis Castillo pitches six innings of three-hit ball, helping the Seattle Mariners beat the Kansas City Royals 2-0 on Thursday

Seattle manager Dan Wilson initiated a replay challenge for a shift violation. Wilson believed Royals second baseman Michael Massey hadn’t been fully on the infield dirt — with one foot perhaps instead encroaching onto the outfield grass — before the pitch was thrown.

Defensive shift limits have been in effect since the beginning of the 2023 season, but challenges to shift violations have been few and far between. In the top of the eighth inning of the Mariners’ 2-0 win over the Royals at Kauffman Stadium,

The Mariners shut down the Royals and held on for a 2-0 win, pulling Seattle even with the Astros for the AL West lead ahead of a massive series in Houston.

After Seattle took a late lead, Royals second baseman Adam Frazier reclaimed it with a go-ahead, two-run homer in the eighth inning. KC also added significant insurance runs as rookie catcher Carter Jensen and superstar Bobby Witt Jr. recorded key RBIs.

The Seattle Mariners are sticklers for the new shift rule. As the Mariners faced he Kansas City Royals on Thursday, Royals' second baseman Michael Massey lined up with his heels slightly touching the outfield grass, which is technically illegal with the new rule implemented this season.

The Seattle Mariners play the Kansas City Royals after Eugenio Suárez had four hits against the Royals on Wednesday.

They say all good things must come to an end. The Seattle lived that lesson in Kansas City on Wednesday night, as they lost 7-5 to the Royals. And it was a doub

The Seattle Mariners and the Houston Astros were separated by a half-game ahead of the Mariners' Thursday contest, but the pair square off over the weekend.