Seattle Mariners Dynasty Sleepers, Breakouts, and Busts

With dynasty season ramping up, I figured it was time to talk about some sleepers, breakouts, and busts for each team. You can find my rankings and reports to see how I value players for your dynasty leagues, but I also feel like it’s helpful to truly identify whether I believe a player can be a breakout or not. Here is where I call my shots on players I think require a call to action in dynasty, whether it be to buy or sell that player.

While you are here, be sure to check out the updated Seattle Mariners top prospect list, updated with new international prospects:

Seattle Mariners Dynasty Sleepers, Breakouts, and Busts

MLB Sleeper: Luke Raley, 1B/OF, 30, 6’4”/235

Raley has averaged 21 home runs and 12 stolen bases per season the last two years despite averaging 430 plate appearances per season. There are contact questions in the profile, and he is likely to hit .240-.250, but the power and speed are interesting for a deeper league target.

The approach is average, as the chase rate has improved and was around 28 percent last season. His heart-swing rate was well north of average at 86 percent and it is where Raley does most of his damage. The overall contact rate looks a little scary, but it is largely because Raley has some of the worst out-of-zone contact in baseball. The good news, most don’t have great quality of contact when they connect on pitches out of the zone. Raley’s 76 percent in-zone contact rate is still not great, but it will play.

The power in the profile is good. Raley brings strong bat speed to the table, which averaged 75 mph last year, 89th percentile for hitters. The 11 percent barrel rate was also impressive despite the inconsistent launch angles.

The foot speed is also really good, which has led to 14 and 11 stolen bases each of the last two seasons. He has only been caught a combined five times. Raley is a sneaky 20 home run, ten stolen base threat who plays well in OBP leagues. He seems to be a bit slept on, but the performance has been steady and good.

MLB Breakout: Victor Robles, OF, 27, 6’0”/193

On a team with few potential breakouts, we turn to Victor Robles who put together the best season of his career in 2024 splitting time between the Nationals and Mariners. While Robles hit just four home runs, he stole 28 bases in 295 MLB plate appearances and slashed a strong .307/.381/.433

Under the hood, there is certainly a reason to be pessimistic about Robles’ power, especially given the 86.7 mph average exit velocity and 28.6 percent hard-hit rate. Both are bottom of the barrel for MLB hitters.

The contact skills are average as Robles had an 81 percent in-zone contact and 75 percent overall mark. While he is aggressive and chases a bit too much, the aggression on pitches in the zone and over the heart of the plate are critical to his success.

The carrying fantasy tool is obviously stolen bases as Robles swiped 34 bases in 36 tries. Given the half season in the Majors, Robles could easily swipe 60 bases and I would not be shocked. The biggest question is how much power does Robles hit for, especially in Seattle, and what kind of average do we get? If you are looking for steals, Robles is a great target in hopes you can get ten home runs to pair with 50 stolen bases if all clicks right.

MLB Bust: Randy Arozarena, OF, 30, 5’11”/185

Arozarena is a really tough choice here. On one hand, Arozarena has had four straight 20 home run/20 stolen base seasons. He feels like a potential lock to do that again. So, why would he be picked here? Well, the move to Seattle is a big concern. After the trade in 239 plate appearances, Arozarena hit just five home runs, so it is possible we see a small tick back in home runs.

We have seen four straight seasons of regression in batting average and Arozarena hit just .219 last season. The contact skills have been questionable for a while, but the in-zone contact has taken a step back the last three seasons. Another problem is Arozarena’s passivity. It is encouraging to see the chase rate drop, but he is also swinging at pitches in the zone, which is eight percentage points less than the MLB average. His heart-swing rate is also well below MLB average.

The power metrics are fine as Arozarena continues to hit the ball hard, having a 90.4 mph average exit velocity last season. The more significant issue is the lack of barrels due to poor launch angle distributions. Arozarena’s 28.4 percent sweet-spot rate was fourth percentile for all hitters.

Arozarena won’t be a bust as you may think about that term. But, I think we see the first season of his career, in which he does not reach 20 home runs. Last season he finished ranked the 156th best player for 5x5 leagues according to Razzball Player rater. It would not shock me if he was a step below that this year with a full year in a tough park to hit in.

Seattle Mariners Prospect Sleeper: Brandyn Garcia, LHP, 24, 6’4”/235, AA

Drafted the in 11th round of the 2023 MLB Draft out of Texas A&M and became a surprising breakout player in 2024. Pitching between High-A and Double-A, Garcia threw 116 innings with a 2.25 ERA and 134 strikeouts.

A sinker/slider arm, Garcia’s sinker ticked up to sit in the mid-90s and showed a strong arm-side run. When Garcia was not missing bats, he kept batted balls on the ground, which he did at a 50 percent rate in 2024.

The slider has also significantly improved from his college days, getting a ton more sweep on the pitch and missing more bats. It sat around 85 mph this season with eight inches of sweep. It is a pretty true two-pitch mix, but the fastball and slider combo work. It will be worth watching if it continues to work as he moves up levels.

Garcia looks like a backend starting pitcher right now, even if he does not develop a third pitch.

Seattle Mariners Prospect Breakout: Josh Caron, C, 21, 6’0”/215, A

Caron was one of the younger college players drafted in the 2024 class, not turning 21 until August 3. He put together an impressive career at Nebraska but took off in 2024, hitting 16 home runs and having 32 extra-base hits in 60 games. Caron put up a slash of .308/.388/.579 while striking out 19 percent of the time.

The underlying data pops for Caron, who had a 110 mph 90th percentile exit velocity and a 114.5 mph max. For reference, those numbers stack up very similarly to Cam Smith of the Cubs and not far behind Nick Kurtz.

Caron shows a solid approach, chasing around 24 percent of the time out of the zone while making contact on pitches in the zone at an impressive 86 percent clip.

Stepping into pro ball for 13 games, Caron looked quite solid with Modesto. He could start in High-A next season and will be 21 years old nearly all year. He is a bat-over-glove catcher, but the bat is quite strong.