Cincinnati Reds vs Seattle Mariners Picks and Prediction for Tuesday, July 21, 2026

The Cincinnati Reds travel to face the Seattle Mariners at T-Mobile Park in Seattle, Washington, on Tuesday, July 21, 2026. The first pitch is scheduled for 9:40 PM ET, with television coverage available on MLB.TV. Cincinnati enters the matchup with a 45-53 record, while Seattle owns a 50-50 mark. The matchup predictor gives the Reds a 55.5% chance to win compared with 44.5% for the Mariners. At the time of this writing the odds were not released. Be sure to check out our free MLB picks before Tuesday night’s game begins.

Starting Pitchers for Cincinnati and Seattle

Chase Burns is scheduled to start for Cincinnati opposite Luis Castillo for Seattle. Burns enters with an 11-1 record, a 2.54 ERA, and a 1.11 WHIP across 102.2 innings. He has allowed 77 hits and 12 home runs while recording 118 strikeouts and issuing 37 walks. Castillo owns a 3-8 record with a 4.93 ERA and a 1.37 WHIP through 87.2 innings. He has surrendered 92 hits and 12 home runs while collecting 81 strikeouts and allowing 28 walks. Cincinnati’s starter holds the advantage in record, ERA, WHIP, innings, hits allowed, and strikeouts.

Cincinnati Turns to a Decisive Starting-Pitching Advantage

The Reds enter Tuesday’s contest with a 45-53 overall record and a 23-25 record away from home. Cincinnati recently earned victories of 9-6 and 7-2 over Colorado while losing the other meeting 10-3. Before those games, the Reds recently suffered losses of 8-4 and 5-3 to Chicago. Cincinnati has won two of its last five games and has scored at least three runs in each contest during that stretch.

Cincinnati is batting .231 as a team with 414 runs, 761 hits, and 129 home runs. The Reds have produced a .311 on-base percentage and a .401 slugging percentage. Their pitching staff owns a 4.57 ERA and a 1.43 WHIP while issuing 427 walks and collecting 793 strikeouts. Opposing hitters have batted .248 against Cincinnati. The Reds have also compiled a 24-33 record in night games.

Cincinnati’s primary strength in this matchup is its power production. The Reds have hit 129 home runs compared with Seattle’s 118 and have scored 12 more runs. Cincinnati also holds advantages in batting average, hits, on-base percentage, and slugging percentage. The team’s overall pitching numbers are weaker than Seattle’s, but the Reds enter Tuesday with a substantial advantage between the scheduled starters.

Seattle Leans on Its Home Record and Team Pitching

The Mariners come into the matchup with a 50-50 overall record and a 29-21 record at T-Mobile Park. Seattle recently earned victories of 6-3 and 4-3 in 10 innings over San Francisco while losing the other meeting 7-0. Before that series, the Mariners recently defeated Tampa Bay 8-2 and lost the other contest 6-1. Seattle has won three of its last five games and is eight games above .500 at home.

Seattle owns a .228 team batting average with 402 runs, 752 hits, and 118 home runs. The Mariners have generated a .309 on-base percentage and a .377 slugging percentage. Their pitching staff carries a 3.61 ERA and a 1.18 WHIP with 249 walks and 862 strikeouts. Opposing hitters are batting .239 against Seattle. The Mariners have posted a 29-34 record in night games.

Seattle’s most important strength is its overall pitching performance. The Mariners hold a 3.61 team ERA compared with Cincinnati’s 4.57 mark, while their 1.18 WHIP is considerably better than the Reds’ 1.43. Seattle has issued 178 fewer walks, recorded 69 more strikeouts, and limited opponents to the lower batting average. The concern is the starting matchup, where Seattle’s scheduled starter enters with a 4.93 ERA against Cincinnati’s 2.54 mark.

Cincinnati Reds vs Seattle Mariners Picks and Prediction

Cincinnati Reds vs Seattle Mariners Pick

• Pick: Cincinnati Reds Moneyline

Cincinnati is the selection based primarily on its starting-pitching advantage. The Reds’ scheduled starter owns an 11-1 record with a 2.54 ERA and a 1.11 WHIP, while Seattle’s starter is 3-8 with a 4.93 ERA and a 1.37 WHIP. Cincinnati also holds the better offensive numbers in most of the supplied categories and receives a 55.5% winning probability from the matchup predictor. Seattle has the stronger bullpen-level team profile and home record, but the starting comparison supports the Reds.

Cincinnati Reds vs Seattle Mariners Total Pick

• Pick: Under

I would take the under if the total is set at 8.5. Cincinnati’s scheduled starter has allowed only 77 hits across 102.2 innings while producing a 2.54 ERA and 118 strikeouts. Seattle also owns a strong 3.61 team ERA, a 1.18 WHIP, and a .239 opponent batting average. The Mariners have scored 402 runs through 100 games and have been held to three runs or fewer in four of their last five contests. Those pitching and scoring numbers support the under.

Final Score Prediction: Cincinnati Reds 4 – Seattle Mariners 3

This prediction was written before the completion of game play on Monday.