Cincinnati Reds vs Seattle Mariners Picks, Prediction, Odds, and Line Movement for Tuesday July 21 2026
The Cincinnati Reds vs Seattle Mariners prediction for Tuesday's matchup at T-Mobile Park looks at a Mariners team riding a three-game winning streak after an 8-0 shutout Monday. Cincinnati sends ace Chase Burns to the mound in an attempt to slow Seattle down, while the Mariners counter with Luis Castillo. For more coverage across the league, check out our MLB picks for additional angles on tonight's slate.
TLDR: Quick Picks and Prediction
- Moneyline Pick: Reds (-108)
- Total Pick: Under 7.5 runs
- Final Score Prediction: Reds 4, Mariners 2
Odds and Line Movement
Current Odds
| Market | Cincinnati Reds | Seattle Mariners |
|---|---|---|
| Moneyline | -108 | -112 |
| Run Line | -1.5 (+160) | +1.5 (-195) |
| Total | 7.5 runs | |
Line Movement - Moneyline
| Date | Time | Cincinnati | Seattle | Public ($, #) |
|---|---|---|---|---|
| 07/21 | 00:58:20AM | -108 | -112 | CIN 82%, 55% |
| 07/21 | 00:58:20AM | -106 | -114 | CIN 81% |
| 07/20 | 09:06:58PM | -106 | -114 | |
| 07/20 | 03:06:39PM | -106 | -114 |
Line Movement - Total
| Date | Time | Over | Under | Public ($, #) |
|---|---|---|---|---|
| 07/21 | 00:58:20AM | 7.5 (-107) | 7.5 (-113) | U94%, O64% |
| 07/20 | 06:19:21PM | 7.5 (-108) | 7.5 (-112) | |
| 07/20 | 03:06:39PM | 7.5 (-106) | 7.5 (-114) |
Reds vs Mariners Key Matchups and Game Preview
Reds Starting Pitching
Chase Burns starts for Cincinnati with an outstanding 11-1 record, 2.54 ERA and 1.11 WHIP across 102.2 innings. The right-hander has recorded 118 strikeouts while allowing only 77 hits, although his 37 walks and 12 home runs surrendered show that Seattle can create scoring opportunities by working deep counts.
Mariners Starting Pitching
Seattle counters with Luis Castillo, who enters 3-8 with a 4.93 ERA and 1.37 WHIP over 87.2 innings. Castillo has allowed 92 hits and 12 home runs while collecting 81 strikeouts against 28 walks, making his current form significantly less dependable than Burns' season-long performance.
Cincinnati Offense
Cincinnati owns the power advantage with 129 home runs and a .399 slugging percentage, while batting .230 with a .310 on-base percentage. Sal Stewart leads the Reds with 20 home runs and 70 RBIs, while Elly De La Cruz is batting .279 with a .352 OBP and .502 slugging percentage.
Sign Up Get $30 Premium Picks Credit + Exclusive Offers
Subscribe Now
Seattle Offense
Seattle is also batting .230 with a .310 OBP, but has produced 119 homers and a .378 slugging percentage. Randy Arozarena is hitting .284 with a .381 OBP, while Luke Raley has supplied 15 homers and Cole Young has driven in a team-high 48 runs.
Cincinnati Injury Situation
Cincinnati's Spencer Steer is day-to-day, while Matt McLain remains unavailable and starting pitchers Nick Lodolo and Brandon Williamson are sidelined.
Seattle Injury Situation
Seattle lists Julio Rodriguez and J.P. Crawford as day-to-day, and losing either would weaken the lineup's run-producing potential. Rob Refsnyder is also unavailable, further reducing the Mariners' offensive depth.
CIN vs SEA Betting Trends
Seattle opened the series with an 8-0 victory Monday, earning its third consecutive win and improving to 51-50, a half-game ahead of Texas atop the American League West. Cincinnati fell to 45-54 and remains 17.5 games behind Milwaukee in the National League Central. Public betting money has leaned toward the Reds, with one snapshot showing 82 percent of bets and 55 percent of money on Cincinnati, while the total has drawn strong under support at 94 percent on the most recent update.
CIN and SEA Injury Report and Things To Know
- Reds infielder Spencer Steer is day-to-day.
- Reds infielder Matt McLain remains unavailable.
- Reds starters Nick Lodolo and Brandon Williamson are sidelined.
- Mariners stars Julio Rodriguez and J.P. Crawford are day-to-day.
- Mariners infielder Rob Refsnyder is unavailable.
- Seattle has won three straight games, including Monday's 8-0 shutout.
Reds vs Mariners Side and Over/Under Picks
Reds Side Pick
Seattle owns the much stronger team pitching numbers, posting a 3.57 ERA and 1.17 WHIP compared with Cincinnati's 4.60 ERA and 1.44 WHIP, but Burns provides the Reds with the clear starting-pitching advantage. The preferred pick is the Reds moneyline at -108.
Cincinnati Total Angle
With Burns' dominant season-long form and Castillo's recent struggles limiting scoring chances, the under 7.5 runs stands out as the preferred total play for this game.
Final Score Prediction
- Reds: 4 runs
- Mariners: 2 runs
This projection lines up with the preferred pick of Reds moneyline and the under 7.5 total.
How to Wager On Reds vs Mariners
For this Reds vs Mariners matchup, the clearest paths are the Reds moneyline and the under 7.5 total, with Burns' dominant form and Castillo's recent inconsistency supporting both plays. Bettors who want additional tools before placing a wager on this game can also explore our AI picks resource, along with our Dimers review and Oddible review for more ways to approach tonight's slate.
Never Tried Picks and Parlays? Now Is Your Chance
- Get your first daily picks package for ONLY $1 using coupon code BUCK
- If the pick loses, we credit your account with 3 Flex Picks
- If the pick wins, we still give you 1 Flex Pick on the house
- Win or lose, you walk away ahead. One dollar. No catch.
Up To $1500 in Bonus Bets Paid Back if your First Bet Does Not Win
New Users – Bet $5 Get $200 in Bet Reset Tokens for 5 Days
New DraftKings Customers: Spend $5+ Get $150 in Bonus Bets *Paid Within 14 Days
