Mariners Minors Report: 8 prospects who shined in April

The month of May is upon us, which makes it’s a good time to check what’s going on in the Seattle Mariners’ farm system.

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The M’s have the most loaded group of prospects in the majors right now with a league-high nine players in Baseball America’s top 100 and seven on MLB’s Pipeline’s top 100 list. Not all of those prospects are off to great starts, but a few of them are, and some lesser-known farmhands are also excelling early on.

Here are several Mariners prospects who delivered a strong month of April.

• Tyler Locklear, 1B, Tacoma Rainiers

Organizational prospect ranking: 11 (per MLB Pipeline)

2025 stats: .317/.400/.485, 11 doubles, two home runs, 17 RBIs, five stolen bases, 12 walks, 27 strikeouts in 26 games

The skinny: After getting a small taste of the big leagues last season, Locklear, 24, seems to be knocking on the door for a major league promotion. He’s 15th in the Pacific Coast League in batting average, 13th in on-base percentage, 11th in hits and sixth in doubles. His strikeout and walk rates in the minors haven’t changed much from last season, but the 2022 second-round pick is hitting 57 points higher than he did in 70 games with Tacoma. The M’s named Locklear their minor league co-hitter of the month for April on Thursday.

• Jared Sundstrom, OF, Arkansas Travelers

Organizational prospect ranking: 24

2025 stats: .278/.371/.438, one double, two triples, two home runs, nine RBIs, eight stolen bases, 11 walks, 16 strikeouts in 20 games

The skinny: Sundstrom, 23, had a strong first full pro season with High-A Everett in 2024, and he’s maintained his numbers at the plate while moving up to Double-A and playing in more pitcher-friendly parks in the Texas League. A 2023 10th-round pick, Sundstrom ranks top 25 in the Texas League in batting average, on-base percentage and OPS, and he’s tied for third in stolen bases.

• Lazaro Montes, OF, Everett AquaSox

Organizational prospect ranking: 2

2025 stats: .268/.413/.585, five doubles, three triples, five home runs, 14 RBIs, two stolen bases, 20 walks, 23 strikeouts in 23 games.

The skinny: Montes is continuing to show the upside his bat has at just 20 years old in the Northwest League. He’s tied for the league leads in extra-base hits, home runs and triples, and he ranks in the top 10 in on-base percentage, slugging and OPS. Montes put up strong numbers in 51 games with Everett last season despite a terrible first month. This year he’s improved on his power, walk and strikeout numbers, and he could be a candidate to move up to Double-A in the near future. The M’s named Montes their minor league co-hitter of the month for April on Thursday.

• Jurrangelo Cijntje, switch-pitcher, Everett AquaSox

Organizational prospect ranking: 9

2025 stats: 0-2 record, 6.75 ERA, 1.62 WHIP, 22 strikeouts, .194 opponents’ batting average, 17 1/3 innings pitched in seven games (four starts)

The skinny: At first glace, the 21-year-old Cijntje’s numbers with Everett aren’t very impressive. But he has been great as a starter, just not as a reliever. In his four starts, Cijntje has a 2.35 ERA, 1.11 WHIP with 19 strikeouts in 15 1/3 innings. However, he’s allowed nine runs over two innings during three relief appearances. The M’s are using Cijntje as a left-handed reliever once between starts to try and take advantage of his switch-pitching abilities, so there’s probably going to be some patience needed with the 2024 first-round pick.

• Tyler Cleveland, RHP, Everett AquaSox

Organizational prospect ranking: Unranked

2025 stats: 0-0 record, 0.00 ERA, 0.57 WHIP, five holds, 12 strikeouts, .077 opponents’ batting average, 12 1/3 innings pitched in eight games

The skinny: Cleveland’s 12 1/3 innings pitched lead all Northwest League pitchers who haven’t allowed an earned run yet this season. The right-hander is one of the older players at his level at 25, but the 2022 14th-round pick does carry some intrigue due to his funky delivery.

• Carter Dorighi, SS, Modesto Nuts

Organizational prospect ranking: Unranked

2025 stats: .397/.481/.460, four doubles, 11 RBIs, four stolen bases, 10 walks, 17 strikeouts, 19 games

The skinny: Dorighi, a 21 year old who went undrafted last season, is off to a blistering start for the Nuts. He leads the California League in batting average and is fourth in on-base percentage.

• Felnin Celesten, SS, Modesto Nuts

Organizational prospect ranking: 5

2025 stats: .307/.376/.413, two doubles, two home runs, 18 RBIs, four stolen bases, nine walks, 12 strikeouts in 18 games

The skinny: Celesten is finally healthy, and he’s not disappointing during his first season with Single-A Modesto. A 19-year-old switch-hitter, Celesten is 12th in batting average and sixth in RBIs in the California League. In just 50 career pro games, he’s hitting .335 with a .920 OPS.

• Ryan Sloan, RHP, Modesto Nuts

Organizational prospect ranking: 8

2025 stats: 0-0 record, 2.92 ERA, 1.22 WHIP, 13 strikeouts, .217 opponents’ batting average, 12 1/3 inning pitched in four starts

The skinny: Sloan, a second-round pick in 2024, has been solid thus far in his pro season at just 19 years old. He holds the second-best ERA among Nuts starters, and he’s pitched at least three innings with one earned run or less allowed over this past three starts. Sloan’s best performance came in his second appearance when he piled up seven strikeouts in 3 2/3 innings.

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