Fantasy managers should monitor September call-ups, including Cardinals' JJ Wetherholt and Angels' Nelson Rada

September roster expansion and a flurry of late-season evaluations have given fantasy baseball managers new options for the final weeks of their seasons, and a handful of prospects stand out as candidates who could deliver meaningful short-term production.

Among the names to watch is St. Louis' top prospect, 22-year-old shortstop JJ Wetherholt, who has hit .312/.424/.523 with 16 home runs, 21 stolen bases and a 66:65 strikeout-to-walk ratio across Double-A Springfield and Triple-A Memphis in 99 games. The Cardinals have fallen out of the playoff race, and the club’s front office turnover — president of baseball operations John Mozeliak announced this will be his final season — could create an opening for the organization to give younger players major-league exposure.

Wetherholt does not require promotion to the 40-man roster to be protected in the Rule 5 draft this offseason, which lessens the club’s urgency to add him to the big-league roster. Still, with injuries to infielders Brendan Donovan and Nolan Arenado and struggles from Thomas Saggese (.190 batting average), the Cardinals could elect to evaluate Wetherholt at the major-league level late in the season, including the possibility of trying him at third base. Any extended run in St. Louis would be of interest to fantasy managers looking for a multi-category contributor.

The Los Angeles Angels have a different profile to monitor. Outfielder Nelson Rada has been productive at Triple-A Salt Lake of late, slashing .333/.440/.429 with a .869 OPS over his past 10 games and recording two doubles, a triple, four runs batted in and seven stolen bases during that stretch. With the Angels out of contention and several outfield options — including Bryce Teodosio and Matthew Lugo — struggling, Rada could be a low-risk, high-reward pick for fantasy squads seeking stolen-base production.

Scouts and analysts caution that Salt Lake plays in the hitter-friendly Pacific Coast League, so power numbers may not translate directly from Triple-A to the major leagues. Still, Rada’s plate discipline and elite speed make him an intriguing candidate for September playing time, particularly if the Angels opt to rest regulars such as Taylor Ward or pursue longer looks at younger players.

Teams across baseball typically use the final month to evaluate prospects and reset for the following season, giving fantasy managers a narrow window to capitalize on short-term call-ups. Not every promotion results in immediate fantasy value, but a three-week spell of everyday at-bats or consistent plate appearances can materially affect playoff outcomes in head-to-head and points formats.

Howard Bender, head of content at FantasyAlarm.com, wrote that mining the minor leagues in September is essential for fantasy managers, noting that a late-season call-up could provide the boost needed during fantasy playoffs. With less than a month remaining in many fantasy seasons, managers are advised to keep a close watch on roster moves, injury updates and team announcements that could clear the way for prospects such as Wetherholt and Rada to reach the majors.

Front offices weigh several factors when promoting a prospect — service-time considerations, roster construction, Rule 5 eligibility and long-term development plans — and those calculations vary by club. For fantasy purposes, the most relevant considerations are playing opportunity and role. Prospects getting everyday looks or regular pinch-running and defensive assignments are likelier to provide immediate fantasy returns than players receiving sporadic late-inning duty.

As the regular season winds down, roster churn often accelerates. Fantasy managers should monitor box scores, transaction logs and official team statements for call-ups and roster moves that could create short-term value, remembering that while not every prospect sticks, the payoff from a timely addition can be decisive in a playoff matchup.