No way am I buying Yusei Kikuchi as a favorite. The left-handed Kikuchi has been one of the worst starting pitchers in the majors during his two-year stint compiling a 5.46 ERA with a 1.52 WHIP in 2019 and a 5.17 ERA with a 1.30 WHIP last season. 
San Francisco just faced a lefty starter on Thursday and scored five earned runs in six innings off Marco Gonzales, a much better pitcher than Kikuchi. Seattle has one of the worst bullpens in the majors, too. 
Giants starter Johnny Cueto isn't the star he was with the Reds, but he's still solid. I consider him the Giants' best starter. Cueto has a 2.41 lifetime ERA against Seattle in three starts. San Francisco's bullpen is better than it showed in its 8-7 extra inning loss to the Mariners on Thursday. 
The Mariners remain without perhaps their most talented player as outfielder Kyle Lewis has a knee injury.