Seattle Mariners infield/outfield prospect Michael Arroyo earned a promotion to Triple-A back on July 7 and has looked like he belongs there, collecting a hit in eight of the 10 games he's played in, going 17-for-45 (.378) with three doubles, a triple, two home runs, and a pair of stolen bases. He's struck out eight times in 51 plate appearances, which is just a 15.7 percent rate (84th percentile), so the 21-year-old does not appear overmatched in that regard either. The Mariners' fourth-ranked prospect offers a solid hit tool with some power to go along with it and some speed to boot, making him an intriguing fantasy asset in both redraft and dynasty formats. At this rate, a late-season debut in the majors looks possible, so managers in deeper leagues could consider stashing him, but if that doesn't happen, look for a productive 2027 in the majors from the 5-foot-10 Colombian.

St. Louis Cardinals pitching prospect Quinn Mathews appears to be on the precipice of a major league debut after a strong season at Triple-A Memphis. The southpaw has been rolling as of late, allowing two earned runs or fewer in eight of his last nine starts, but for the most part, he's been pitching well all year. Take away his worst three starts of the year, the Cards' sixth-ranked prospect owns a 1.89 ERA and 0.98 WHIP in the other 15 starts. Not to mention 101 strikeouts in 85 total innings pitched are also very usable for fantasy. Opponents are batting .171 off of him on the year, so if he can translate some of that success to the majors, he could be a productive pitcher for fantasy over the final two months of the season. Look for the 25-year-old to debut in the coming weeks, and managers in deeper 12-team leagues should consider stashing him in an NA spot ahead of time.

The Cleveland Guardians reinstated third baseman Jose Ramirez (hand) from the 10-day injured list on Wednesday and optioned outfield prospect Kahlil Watson to Triple-A Columbus in a corresponding move, according to Tim Stebbins of MLB.com. Ramirez has skipped a minor-league rehab assignment and will start at third base and bat in the two-hole in his return on Wednesday against the division-rival Minnesota Twins and right-hander Bailey Ober. Despite being out for over five weeks with a broken hamate bone in his hand, Ramirez should be returned to all starting lineups immediately against a pitcher whom he knows well in his career. In 28 career at-bats against Ober, J-Ram is hitting .321 with a 1.013 OPS, two home runs, and five RBI. The 33-year-old switch-hitting Dominican has missed valuable time in 2026, and he'll return to a .239/.339/.418 slash line with a .757 OPS, 10 home runs, 33 RBI, 42 runs scored, and 24 stolen bases across 268 at-bats. Ramirez's power might not come back right away, but he should still be useful for his speed and will be a must-start once again in all fantasy formats.

Tampa Bay Rays outfield prospect Jacob Melton is hitting .327 at Triple-A Durham since his return from the injured list back on June 24, with four doubles, three home runs, three steals, and a 7:11 BB:K over 13 games. For the season, the former second-rounder is hitting .272 with a solid .377 on-base percentage thanks to a 14.4 percent walk rate. The slugging percentage is good, too, at .500, but it is the speed that makes him intriguing for fantasy. The Rays' fifth-ranked prospect has swiped 20 bases in just 33 games for the Bulls, utilizing his 90th-percentile sprint speed. The 6-foot-2 slugger debuted with the Astros in 2025, showing off his speed then as well, with seven steals during his limited action. The 25-year-old could get the call to the majors again in the coming weeks, and with his speed, he's one of the top stash options for steals, with the potential to hit for a decent average and a little bit of pop to go along with it.