Rookie Mike Montgomery has been a compelling story for the Mariners. The lefty had been pitching great with a 1.62 ERA during his first seven big league starts after spending seven seasons in the minors. But regression has caught up to Montgomery, who had been pitching way over his head.




In his last three starts, Montgomery is 0-2 with a 9.22 ERA. The Diamondbacks are more dangerous playing in an American League park - where they can DH their only defensive liability Yasmany Tomas. They rank seventh in weighted on-base average (WOBA) versus southpaws.




Robbie Ray also has looked good since his call-up from the minors. He didn't look good in his last start this past Wednesday, but he had a 1.42 ERA in his previous two starts and has a 2.72 ERA on the season. He'll be helped pitching in spacious Safeco Field.




Ray has yet to yield an earned run during two starts versus AL clubs this season spanning 14 2/3 innings. He's backed by an Arizona defense that ranks second to the Royals in defensive runs saved.




The Mariners are 5-13 the past 18 times when favored between $1.10 and $1.50.