Seattle Mariners vs Kansas City Royals Prediction, Odds and Picks for Today, 05/23/26

I favor the Seattle Mariners over the Kansas City Royals as the teams face off Saturday. George Kirby is the scheduled starter for Seattle. Kirby has made 10 starts spanning 62.2 innings of work so far this season. He has posted a 3.45 ERA in that span with a 3.54 FIP and 3.20 xERA to support his success. Kirby is fresh off his worst start of the season against the Padres, allowing 6 earned runs and 2 home runs in that outing. Prior to that start Kirby had a 2.84 ERA and had allowed 2 or fewer earned runs in 6 straight outings. I expect him to bounce back well against a Royals lineup ranking just 19th in wOBA with a 94 wRC+ against right-handed pitching this season. 

Stephen Kolek is the starter for the Royals on Saturday. This will be Kolek’s 4th appearance of the season. He has tossed 17 innings through his first 3 starts with mixed results. He did post a quality start with 6 innings and 3 earned runs against the Guardians in his season debut. His 2nd start was his worst, allowing 5 earned runs in 4.2 innings to the White Sox. Kolek was sharp in his last start, tossing 6.1 scoreless frames in a win over the Cardinals. He was highly effective in generating ground balls, but his low whiff rate and his tough matchup have me worried for Saturday. Seattle enters this game sitting 5th in wOBA with a 116 wRC+ against right-handed pitching and I expect them to win this game.

Seattle Mariners vs Kansas City Royals prediction: Mariners ML (-137) available at time of publishing. Playable to -140 odds.