Phillies vs. Mariners Monday Betting Prediction - Philadelphia back home after long trip

The Philadelphia Phillies (71-53) can finally unpack their suitcases following a 10-game, three-city road swing.

The Phillies finished off a 6-4 trip with a thrilling 11-9 victory over the Washington Nationals on Sunday to grab a four-game split with their division rivals.

Philadelphia welcomes in the Seattle Mariners (68-57) for a three-game interleague set at Citizens Bank Park on Monday with first pitch at 6:45 p.m. ET.

MATCHUP NOTES

The road trip started on a high note for the Phillies, sweeping the Rangers in Arlington. Following a win in the series opener at Cincinnati, Philadelphia lost four of the final six games.

In Sunday's win at Washington, the Phillies jumped out to a 6-0 lead before the Nationals scored six unanswered runs to tie the game at 6-6. Philadelphia tallied the next five runs to open up an 11-6 advantage before Washington plated three runs in the bottom of the ninth.

Alec Bohm and Nick Castellanos went deep for the Phillies, who scored at least 10 runs in a game for the first time since a 13-3 blowout of the Orioles on August 4.

WELCOME BACK, ALEC BOHM! pic.twitter.com/mj3kAz2je2
— Philadelphia Phillies (@Phillies) August 17, 2025

The Phillies enter Monday's action with a five-game advantage over the New York Mets atop the NL East standings. Milwaukee has built a 7.5-game lead for the best record in the National League, ahead of the Phillies and Los Angeles Dodgers.

Philadelphia owns a 37-21 record at Citizens Bank Park, including a 7-2 mark in the last nine home series openers.

The Mariners dropped two of three to the Mets, capped off by Sunday's 7-3 defeat in Williamsport, Pennsylvania.

Seattle closed its last homestand at 9-1 before losing consecutive road series to Baltimore and New York.

Mariners' catcher Cal Raleigh knocked out his league-leading 47th homer in Sunday's loss as Seattle sits 1.5 games behind Houston for first place in the AL West.

PITCHING MATCHUP

Ranger Suarez (8-6, 3.28 ERA) looks to get on track after allowing 19 hits and 11 runs in his last two starts. The Phillies lost to the Orioles and Reds in those outings, as Philadelphia is 2-4 in his past six trips to the mound.

Suarez has been tagged for 14 runs in his last three starts at Citizens Bank Park. He faces a Seattle squad that is batting .239 against left-handed pitching this season.

Suarez has yielded a 29.1% hard-hit rate, ranking in the 99th percentile in MLB. He will be tested against the likes of Raleigh (50.9% hard-hit rate) and third baseman Eugenio Suarez (50.2%), who are two of the top five home runs hitters in MLB.

The Mariners send out right-hander Logan Gilbert (3-4, 3.31 ERA), who looks to turn around his poor road numbers. Gilbert owns a 4.86 ERA away from Seattle, compared to a 2.22 ERA at home.

In his last start at Baltimore, Gilbert pitched well by allowing two runs in 6.1 innings, but the Mariners lost in walk-off fashion, 4-3.

Seattle is 4-1 this season when Gilbert takes the mound after a loss in his last start.

FIRST FIVE INNING TRENDS

The Phillies led through five innings on Sunday, but have held the lead halfway through in consecutive games once since the All-Star break.

Suarez owns a 9-6-3 mark in the first five innings, including an 0-3-1 mark in his past four home starts.

The M's have struggled in the first five innings with Gilbert on the hill, posting a 5-8-4 record.

BETTING OUTLOOK

DraftKings has listed the Mariners as a -115 favorite with the total set at 8 runs.

Gilbert allowed one run and struck out seven batters at home against the Phillies last season. Seattle lost, 6-0 as Philadelphia broke out for five runs late.

Seattle has posted an impressive 8-1 mark in its last nine away series openers. This is a good spot to back the Mariners at a short price against the Phillies off a long road swing.

BEST BET: Mariners -115