Royals vs Mariners Prediction 9/18/25 MLB Picks Today

The Seattle Mariners and the Kansas City Royals meet Thursday in MLB action from Kauffman Stadium. We will look at this from a betting perspective and determine the best bets for this game. Here’s a Royals vs Mariners Prediction.

Starting Pitching Matchup

The Seattle Mariners will send out Luis Castillo for the start here and Castillo is 9-8 with a 3.76 ERA and 149 strikeouts this season. In his last five starts against Kansas City, Castillo is 2-1 with a 4.31 ERA and 22 strikeouts. Stephen Kolek will get the nod here and Kolek is 5-5 with a 3.71 ERA and 67 strikeouts this season. This will be Kolek’s second career start against the Mariners.

Seattle Mariners Recap

The Seattle Mariners come into this game looking to rebound from their 7-5 loss at the hands of the Royals on Wednesday to sit at 83-69 this season. After this series, the Mariners will head on the road for a series against the Houston Astros.

Mariners Have Double-Digit Win Streak Snapped

Jorge Polanco has 116 hits including 24 home runs and 72 RBIs while Cal Raleigh has 134 hits with 21 doubles, a team-high 54 home runs and 115 RBIs. Randy Arozarena has 137 hits with 30 doubles, 27 home runs, 73 RBIs and 28 stolen bases. Julio Rodriguez also has 165 hits with 30 doubles, 4 triples, 30 home runs, 91 RBIs and 27 stolen bases. J.P Crawford has 142 hits with 23 doubles, 10 home runs and 52 RBIs.

Why the Seattle Mariners will win

• The favorites have won each of the Mariners’ last 10 games.
• The Royals have lost each of their last six Thursday day games against AL West opponents that held a winning record.
• The favorites have covered the run line in each of the Mariners’ last four games.
• The Royals have failed to cover the run line in six of their last seven home games following a win.

Seattle Mariners Player Prop Facts

• Cal Raleigh has hit at least one home run in three of the Mariners’ last four road games.
• Luis Castillo has recorded five or more strikeouts in each of his last nine Thursday appearances with his team as a favorite.
• Victor Robles has recorded at least one hit in each of his last 14 appearances in day games.
• Jorge Polanco has recorded at least one Double in seven of the Mariners’ last eight games as favorites.
• Cal Raleigh ranks 1st in the league in Home Runs (56) this season.

Kansas City Royals Recap

The Kansas City Royals come into this game looking to build on their win over the Mariners from Wednesday’s game to improve to 76-76 this season. After this series, the Royals will welcome the Toronto Blue Jays to town for a series.

Royals Looking To Keep Momentum Going

Bobby Witt Jr. has 166 hits with 41 doubles and 36 stolen bases along with 6 triples, 22 home runs and 79 RBIs while Vinnie Pasquantino has 151 hits with 27 doubles, a triple, 30 home runs and 104 RBIs. Maikel Garcia’s added 161 hits with 36 doubles, 5 triples, 16 home runs and 70 RBIs and 23 stolen bases and Salvador Perez also has 34 doubles, 28 home runs and 89 RBIs but also has 115 strikeouts so far this season.

Why the Kansas City Royals will win

• The home team has won eight of the Mariners’ last nine games.
• The Mariners have lost five of their last six games as road favorites against American League opponents following a loss.
• The Mariners have failed to cover the run line in each of their last eight Thursday games against AL Central opponents.
• The Royals have covered the run line in nine of their last 11 games as underdogs against AL West opponents.

Kansas City Royals Player Prop Facts

• Salvador Perez has hit at least one home run in three of the Royals’ last four games.
• Bobby Witt Jr. has recorded at least one hit in each of the Royals’ last 12 games against AL West opponents that held a winning record.
• Bobby Witt Jr. ranks T3rd in the league in Hits (167) this season.

Total Runs Facts

• Each of the last 11 games between the Mariners and Royals at Kauffman Stadium have gone OVER the total runs line.
• Each of the Mariners’ last six road games after playing the previous day have gone OVER the total runs line.

Royals vs Mariners Prediction

I’m on the Mariners here. The Mariners fell flat in Wednesday’s matchup, but this is still a red-hot Mariners offense that’s been bringing the heat in recent games. I just don’t trust Stephen Kolek, even at home, to be able to slow them down here. I think Seattle does enough to start a new win streak as they’re getting ready for a huge division set upcoming. Give me Seattle in this one.