Seattle Mariners vs Tampa Bay Rays Prediction, 9/1/2025 MLB Picks, Best Bets & Odds

Game: Seattle Mariners vs Tampa Bay Rays

Date: Monday, September 1, 2025

Location: George M. Steinbrenner Field in Tampa, FL

TV: FanDuel Sports Network Sun

Odds/Point Spread: Seattle (-275) Tampa Bay (+220)

George M. Steinbrenner Field is the location where the Tampa Bay Rays (64-69) will try to defeat the Seattle Mariners (72-62) on Monday. The line on this matchup has Seattle at -275 while Tampa Bay is sitting at +220. The over/under is set at 8.5. The starting pitchers will be Luis Castillo and Shane Baz.

The Mariners have accumulated 183 two-baggers as a team and have knocked 191 balls out of the park. Seattle is slugging .410 and have been called out on strikes 1,198 times, while being walked on 450 occasions. As a squad, the Seattle Mariners are scoring 4.6 runs/g, which has them sitting at 11th in the league. They have recorded 591 RBI's in addition to 1,100 base knocks for the year, while their team batting average is sitting at .241. They have earned 616 runs scored and hold an on-base percentage of .317.

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Their K/BB ratio is 2.84 and their pitching staff has earned a collective WHIP of 1.26. Mariners pitchers have allowed 162 home runs in addition to 591 runs in total (18th in the league). Seattle has surrendered 1,121 base knocks (8.3 per 9 innings) and 534 earned runs. The Mariners have compiled a team ERA of 3.97 so far this year (17th in MLB), and their staff has rung up 1,146 hitters. Their pitching staff has walked 403 players from the other team and their FIP comes in at 4.12 as a unit on the campaign.

Mariners bullpen pitchers have gone to the mound with runners on 112 times and also have had 181 appearances in high leverage situations. The relief pitchers have tallied 74 holds this year (14th in the league). The Mariners relief pitchers have earned a save rate of 62.5% and have come into the game in 130 save situations. They have compiled 35 saves on the season and have missed out on 21 out of their 56 save opportunities. The relief pitchers have inherited 123 base runners this season and 25.2% of those runners ended up crossing the plate. The Mariners have dispatched 452 relievers to the hill this season.

The San Francisco Giants have earned 3,631 putouts on the campaign, in addition to 1,131 assists and 55 errors. Their fielding percentage is holding at .989 which has them sitting 4th in pro baseball, and have a total of 99 double plays. The Mariners have turned 70.3% of baseballs in play into outs in their 10,893 innings on the diamond, ranking them 12th in professional baseball.

Castillo (81-83 career mark) sits with a FIP of 3.52 and he has faced 5,719 opposing hitters in the major leagues. He has conceded 1,191 base knocks (7.8 hits per 9 innings) and has 450 walks. His earned run average is 3.58 (549 ER's allowed) and he has a career WHIP of 1.188. Castillo has taken the mound for 1,381 frames and has earned 1,464 strikeouts thus far in his career.

Tampa Bay has accumulated 149 HRs over the course of the season to go along with 564 runs batted in. They have put up 202 two-baggers, while walking 386 times as well as scoring 596 runs. The Tampa Bay Rays have accounted for an OBP of .314 in addition to a team batting average of .251 this season. The Rays have a slugging percentage of .401 and they are recording 4.48 runs per outing (13th in baseball). They have been called out on strikes on 1,138 instances (13th in MLB) and have earned 1,129 hits.

The Rays are sitting with a team WHIP of 1.211 in addition to having a FIP of 4.24 as a squad on the campaign. Their strikeout to walk ratio is 8.70 (1,142 strikeouts vs 378 free passes). They come in at 6th in baseball as a pitching staff in total hits given up with 1,047. They have allowed 177 long balls and they relinquish 4.27 runs per 9 innings (13th in the league). The Tampa Bay pitching staff have surrendered 558 runs this year while holding an ERA of 3.96 (518 earned runs surrendered).

Tampa Bay has called on bullpen pitchers to enter the contest in 50 save chances and they have come away with 28 saves. They sit at 26th in the league with a save percentage of 56.0%, and they have dispatched 418 bullpen pitchers to the mound on the year. Their bullpen pitchers have stepped onto the hill 124 times in high leverage situations and also on 93 occasions with runners on. Tampa Bay relievers hold an inherited score rate of 32.6% out of 135 inherited runners. Sitting with 124 save situations, the Rays have tallied 73 holds in addition to 22 blown saves.

The Tampa Bay Rays have gotten 122 double plays and have a fielding percentage of .987 (11th in MLB). The Rays have racked up 1,178 assists, 62 errors and have accumulated 3,532 putouts for the year. In their 10,596 innings on the field, the Rays have a defensive efficiency of 71.0% (5th in MLB).

Baz (15-16 career mark) has a 4.38 earned run average and has surrendered 7.9 hits per 9 innings. He has a K/BB ratio of 2.87 and he has gone up against 1,102 hitters in his pro baseball career. He has given up a total of 128 earned runs while earning a WHIP of 1.227 and a FIP of 4.3. So far in his MLB career, Baz has allowed 230 hits while he has accumulated 267 punch outs in 263 innings pitched.

Who will win tonight's MLB game against the spread or moneyline?

Guy Bruhn's Pick: Take Tampa Bay (+220)

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