5 Mariners Prospects Most Likely to Be Traded Next After Caleb Ferguson Deal to Strengthen Bullpen

The Seattle Mariners made their first move to bolster their bullpen by acquiring Caleb Ferguson, but the front office may not be done dealing yet. With one of baseball’s deepest farm systems featuring eight Top 100 prospects, Seattle has significant trade ammunition to pursue additional upgrades.

Speculation is intensifying around which highly-touted prospects might be sacrificed to strengthen the MLB roster for a postseason push. Names like Harry Ford, Michael Arroyo, and Lazaro Montes could headline trade packages as the August deadline approaches.

While Seattle values its young talent, the organization must balance future potential with immediate needs. The Ferguson trade may just be the opening act in a series of moves that could reshape both the Mariners’ roster and prospect pipeline.

5 Seattle Mariners Prospects Most Likely to Be Traded After Caleb Ferguson Bullpen Move

The Seattle Mariners made their first significant trade deadline move by acquiring left-handed reliever Caleb Ferguson from the Pittsburgh Pirates, but industry sources expect more deals coming as Seattle seeks to bolster their playoff push. With one of baseball’s deepest farm systems featuring eight Top 100 prospects, Seattle has ample trade capital to address roster needs. Here are the five most likely prospects to be dealt next.

The Mariners’ front office operates with clear priorities – they’ll trade positional surplus for pitching help without touching their true blue-chip prospects. Watch for deals involving catchers and middle infielders particularly.

1. Harry Ford: The Blocked Catcher With Elite Trade Value

Ranked as Seattle’s No. 4 prospect, Harry Ford presents the most fascinating trade dilemma. The 22-year-old catcher has demolished minor league pitching (.287/.410/.483 slash line in AA) but remains blocked by All-Star Cal Raleigh. Ford’s ability to play outfield and second base increases his versatility – and his trade value.

• 2025 Stats (AA): .287/.410/.483, 12 HR, 15 SB
• Scouting Grades: Hit: 55 | Power: 50 | Run: 60 | Arm: 55 | Field: 50
• Potential Suitors: White Sox, Marlins, Guardians

Multiple contenders need catching help, and Ford represents the best available option who’s nearly MLB-ready. The Mariners must decide whether to keep him as Raleigh insurance or capitalize on his peak value.

I’ve watched Ford since his draft day – his energy is contagious but Raleigh isn’t moving. Trading him for bullpen help now could hurt in 2026, but might secure October baseball this year.

Mariners’ Middle Infield Surplus Creates Trade Opportunities

2. Michael Arroyo: The Rising Star With No Clear Path

Few prospects have boosted their stock more than 20-year-old shortstop Michael Arroyo. The right-handed hitter has torn through two levels this season with a combined .318 average and .912 OPS. However, with Seattle’s infield locked up through at least 2027 (J.P. Crawford, Jorge Polanco, Colt Emerson), Arroyo becomes prime trade bait.

Arroyo’s hit tool reminds me of a young Jose Altuve. Seattle could regret trading him, but middle infield is their deepest position group. Perfect piece to headline a deal for frontline pitching.

The Pitching Prospects Who Could Be Moved

3. Emerson Hancock: Former First-Rounder Needing Fresh Start

Once considered Seattle’s top pitching prospect, Hancock has battled injuries and inconsistency since being drafted 6th overall in 2020. The right-hander shows flashes of brilliance (3.12 ERA in July) but hasn’t developed as hoped. At 25 years old, he’s becoming old for a prospect.

Why he’s tradable:

• Struggles with fastball command (4.2 BB/9)
• Diminished velocity since college
• Multiple IL stints for shoulder issues

A rebuilding team might bet on Hancock’s pedigree and make him a centerpiece in a smaller deal.

Hancock still has MLB starter upside, but Seattle’s rotation is crowded. Trading him now before he loses prospect eligibility makes sense, even if the return is modest.

4. Teddy McGraw: Power Arm With Control Questions

The 22-year-old righty has one of the system’s best fastballs (tops at 99 mph) but struggles to harness it. McGraw’s development stalled after Tommy John surgery in 2023, but his raw stuff could entice teams.

Scouting Report: McGraw’s ceiling remains high – if a team believes they can fix his mechanics, he could develop into a frontline starter. More likely, he becomes a power reliever, which Seattle already has in abundance.

McGraw is exactly the type of prospect Seattle should package in deals – high upside but redundant in their system. Think of him as the modern “player to be named later” in bigger trades.

The High-Risk, High-Reward Bat

5. Lazaro Montes: Developing Power Hitter With Strikeout Concerns

The 20-year-old Cuban outfielder possesses 70-grade raw power but strikes out nearly 30% of the time. Montes crushed 20 homers in A-ball but faces questions about handling advanced pitching.

• Pros: Elite exit velocities, improved plate discipline, strong arm
• Cons: Below-average speed, defensive limitations, long swing

Montes’ Futures Game appearance increased his visibility. Rebuilding teams might overvalue his power potential in trade talks.

Montes is three years away from contributing, if ever. For a contender like Seattle, flipping him for MLB-ready talent aligns with their window. But his ceiling is tantalizing.

Who Should Stay Untouchable?

While Seattle has depth to trade from, certain prospects should remain off-limits:

Jerry Dipoto has proven he knows when to hold prospects (Julio) and when to cash them in (Kelenic). This front office earns our trust to make the right deadline moves.

What Will the Mariners Target in Return?

After addressing the bullpen with Ferguson, Seattle still needs:

1. Consistent right-handed power bat
2. Back-end starting pitcher
3. Bench depth with positional flexibility

The ideal trade package would involve Ford or Arroyo headlining a deal for controllable MLB talent rather than short-term rentals. Seattle’s competitive window is just opening – they shouldn’t sacrifice long-term success for marginal 2025 upgrades.

Watch for Seattle to pursue the Marlins’ Jazz Chisholm Jr. or Tigers’ Riley Greene. Both are young, controllable hitters who’d cost multiple top prospects but fit the roster perfectly.

The Delicate Balance of Buying While Building

Seattle’s front office faces a challenging calculus – how much future to mortgage for present success. Their 2021 trade of Adam Frazier serves as cautionary tale of overpaying at the deadline. However, with Julio Rodríguez entering his prime, the time to contend is now.

The Mariners have the prospect capital to make significant upgrades without completely emptying their farm system. The next two weeks will reveal whether they lean conservative or make franchise-altering moves.

Remember 2014 when Seattle held onto Taijuan Walker instead of trading for David Price? Sometimes the best moves are the ones you don’t make. This year’s team needs help, but must stay disciplined.