Red Sox vs Mariners Prediction 4/22/25 MLB Picks Today

The Seattle Mariners and the Boston Red Sox meet Tuesday in MLB action from Fenway Park. This will be the first installment in a three-game series. Here’s a Red Sox vs Mariners prediction. We will look at this from a betting perspective and determine the best Red Sox vs Mariners pick.

Seattle Mariners Betting Preview

Seattle got their season started with a 2-2 split in four games versus the Athletics, then fell in two of three versus the Detroit Tigers. The Mariners would then fall in a sweep by the San Francisco Giants before a series win over the Astros. Seattle swept the Texas Rangers next and beat the Reds in two of three. The Mariners would split their first two weekend games versus the Blue Jays 3-1 (loss) and 8-4 (win). In the Saturday victory, Seattle got home runs from Rowdy Tellez (four RBI) and Ben Williamson (two runs; two hits). Starter Logan Gilbert went 4.2 innings with two earned runs.

On Sunday, Seattle scored six runs across the first two innings in an eventual win of 8-3. Dylan Moore (solo; two hits), Cal Raleigh (two RBI), and Rowdy Tellez (two RBI) each had home runs in the victory. Starter Luis Castillo put up 5.0 innings with three earned runs on 10 hits and two walks.

As a starter for Tuesday’s game, it’s looking like the Mariners will turn to Bryce Miller. So far this year, Miller is 1-2 with a 3.43 ERA in four starts. Miller has a 21-17 overall record in his career, with a 3.52 ERA in 60 starts total.

Boston Red Sox Betting Preview

Over on the Red Sox’ side, they opened the 2025 campaign with a four-game series loss versus the Texas Rangers, then a series win over the Baltimore Orioles. Boston would sweep the St. Louis Cardinals before losing three of four versus the Blue Jays. The Red Sox lost a three-game “laundry series” versus the White Sox, then won a set versus the rival Rays. Following two revenge wins over the other Sox last weekend, in the Sunday game, Boston suffered their first defeat of the series. The Red Sox gave up six runs in the final three frames on the way to an 8-4 loss. Wilyer Abreu came away with a homer and three RBI in the defeat, while Tanner Houck posted 6.0 innings with two earned runs on three hits and two walks alongside seven strikeouts.

On Monday in the finale, the Red Sox scored three runs in the third inning on the way to a 4-2 victory. Rob Refsnyder bagged a solo home run, while Kristian Campbell had two RBI on two hits. Trevor Story added three hits, a run, and one RBI as well. Starting pitcher Walker Buehler finished with 7.0 innings, one earned run, four hits, three walks, and nine strikeouts.

In the starter slot for Tuesday, Boston will send out Brayan Bello. This will be Bello’s 2025 season debut. Last season, Bello posted a 14-8 record with a 4.49 ERA in 30 starts. Over his career, Bello is 28-27 with a 4.42 ERA in 71 games (69 starts).

Why the Boston Red Sox will win

• The Mariners have lost each of their last nine games at Fenway Park following a win.
• The Red Sox have won each of their last nine games as favorites against the Mariners.
• The Mariners have failed to cover the run line in each of their last six games against the Red Sox following a win.
• The Red Sox have covered the run line in seven of their last eight night games against the Mariners following a win.
• The Mariners have lost the first inning in three of their last four road games against AL East opponents.
• The Red Sox have led after 5 innings in each of their last six games.
• The Mariners have trailed after 3 innings in each of their last six night games against AL East opponents that held a winning record.

Why the Seattle Mariners will win

• The Red Sox have lost four of their last five games as home favorites against American League opponents following a home win.
• The Mariners have won three of their last four games as underdogs.
• The Mariners have covered the run line in seven of their last eight games against teams that held a winning record.
• The Red Sox have failed to cover the run line in each of their last five games as home favorites against American League opponents following a home win.
• The Red Sox have trailed after 5 innings in each of their last three games against AL West opponents.
• The Mariners have led after 3 innings in four of their last five night games against American League opponents that held a winning record.

Total Runs Facts

• Nineteen of the Red Sox’s last 21 games as favorites against the Mariners have gone OVER the total runs line.
• Four of the Mariners’ last five night games against AL East opponents have gone UNDER the total runs line.
• The ‘Inning 1 OVER 0.5 runs’ market has hit in each of the Mariners’ last nine games.
• The ‘Inning 1 OVER 0.5 runs’ market has hit in four of the last five games between the Mariners and Red Sox at Fenway Park.

Red Sox vs Mariners Prediction

I’ll lean toward Boston. A lot of this game is going to depend on how Bello looks in his debut, however. He’s coming off the 15-day Injured List after dealing with a right shoulder strain since early on in Spring Training. The plan is—hopefully—to keep Bello in there for around 5.0 innings on Tuesday if all goes well. Provided he’s able to accommodate manager Alex Cora’s intentions, the Sox should soon be getting more good news with the impending returns of Lucas Giolito and Kutter Crawford.

The Red Sox started out hot in their win on Monday, eventually posting eight team hits. Outside of Aroldis Chapman’s earned run allowed (1.0 innings), the bullpen backed up Buehler very well. There were a handful of hitters who came up empty on the day, though, so I’d like to see Boston’s offense spread itself out a little more on Tuesday.