Philadelphia Phillies starting pitcher Andrew Painter has turned things around lately, and he's back on the fantasy radar as an appealing waiver wire target for the month of September. Painter owns a 5.55 ERA with a 1.37 WHIP over 21 outings this year. However, over just his last seven starts, he has a 3.12 ERA with 8.5 K/9 and just 2.9 BB/9. Two of his last three outings have gone seven innings with one or fewer runs. In his most recent start on Wednesday, he went seven shutout innings with six strikeouts, two hits, and no walks. Painter isn't currently a top-85 starter in RotoBaller's rest-of-season fantasy baseball rankings, but that will change if he continues to pitch at such a high level. There's a real opportunity for fantasy managers to pick up Painter off the waiver wire and reap the rewards going forward. As it stands, he's rostered in just 24% of leagues.

From RotoBaller

The Seattle Mariners are promoting top infield prospect Michael Arroyo to the major leagues prior to today's game against the Athletics, according to Daniel Kramer of MLB.com. Arroyo ranked as the Mariners' No. 3 prospect in the latest MLB Pipeline farm system rankings. He was originally signed as an international free agent out of Colombia in 2022. He was promoted from Double-A to Triple-A in the middle of the 2026 season, slashing .283/.359/.471 with 18 home runs, 81 RBI, 17 steals, and 117 wRC+ between the two affiliates. He also racked up an 8.1% walk rate and a 16.4% strikeout rate in the minors. Arroyo played the left side of the infield early in his minor league career, but he has only played second base and left field in 2026. He'll make his MLB debut on Sunday afternoon, batting eighth and playing second base.

From RotoBaller

Minnesota Twins outfielder Walker Jenkins has been relatively quiet at the plate since being called up for his MLB debut, but he still possesses the upside necessary to be an everyday fantasy baseball option. Therefore, fantasy managers should still consider picking him up off the waiver wire for the month of September, especially in deeper leagues. He owns a .590 OPS through eight games, and he has already recorded both his first home run and his first stolen base. He's striking out at a suboptimal 21.4% clip, but he's also showing on-base skills with his 17.9% walk rate. Over a larger sample size, Jenkins should pan out to be a productive fantasy baseball outfielder. As it stands, he's available to grab off the waiver wire in 89% of leagues.

From RotoBaller

Minnesota Twins shortstop Kaelen Culpepper has been fantastic at the plate ever since being called up for his MLB debut less than one month ago. Culpepper has played in 24 games (all at shortstop), and he's had no trouble living up to the hype that he possessed as a top prospect. So far, he owns a .307/.361/.466 slash line with three home runs, 10 RBI, a 6.2% walk rate, a 19.6% strikeout rate, and 133 wRC+. He's slugged eight extra-base hits, and although he's walking less than he did in the minors, his strikeout rate hasn't increased by much since his promotion. Culpepper's near-everyday role and impressive offensive contributions have helped him emerge as a top waiver wire option in fantasy baseball. He's still available in 89% of fantasy leagues, and he ranks as the #24 shortstop in RotoBaller's rest-of-season rankings.

From RotoBaller

Kansas City Royals catcher Carter Jensen has been swinging a hot bat lately, and he's on the fantasy radar as a very appealing waiver wire target. Over his last six games, Jensen is 9-for-23 with three home runs, six RBI, two walks, and five strikeouts. The bulk of his hits have been of the extra-base variety. In addition to his three homers, he's slugged three doubles and a triple during that six-game window. Over the full season, he has a .755 OPS with 22 homers, a 10.9% walk rate, a 28.1% strikeout rate, and 107 wRC+. Jensen gets the day off Sunday, but he's expected to be back in the lineup Monday against the Diamondbacks. In doing so, he'll look to extend his on-base streak to 12 games. He is rostered in 49% of leagues and currently ranks as the #8 catcher in RotoBaller's rest-of-season fantasy baseball rankings. Managers looking to strengthen or solidify their catcher position should consider picking up Jensen off the waiver wire if he's available.

From RotoBaller

Seattle Mariners starting pitcher Kade Anderson was called up to make his MLB debut two weeks ago. His three starts since the call-up haven't been otherworldly, but he still has the strikeout upside necessary to make him an impactful starting pitcher in fantasy baseball for the final stretch of the season. Anderson has a 5.40 ERA through his three starts, but the 3.17 FIP doesn't look quite as bad. The ball-in-play metrics are solid, but we'd like to see him harness his strikeout, walk, and home run rates over a larger sample size. His 6.60 K/9 rate in the majors is essentially half of his rate from the minors this year, and his 4.20 BB/9 and 1.80 HR/9 rates are both key reasons why his ERA is so high. Getting called up midseason could be the main reason why Anderson has been a little shaky in the majors, and we have no concerns about his ability to produce long-term. Meanwhile, in the short-term, there's still a window for him to turn things around if he can attack the strike zone and miss more bats. He's an intriguing stash in September because if he makes those corrections, he'll have a huge fantasy baseball impact. He currently ranks as the #30 starter in RotoBaller's latest rest-of-season fantasy baseball rankings.

From RotoBaller

Pittsburgh Pirates outfield prospect Edward Florentino homered on Saturday for his second homer in four games with High-A Greensboro. Florentino has had a good minor league season at age 19 between two minor league levels, combining to hit .236 with 27 homers and 84 RBI with 84 runs scored and 11 stolen bases. The left-handed hitter is the No. 2 prospect in the Pirates system with a 50-grade hit tool, 60-grade power, and 55-grade speed. At 6-foot-3 and 200 pounds, Florentino is a bit wiry but has room to put on some more muscle, which will only likely add to his power. His average is a bit low this season, but that could be due to adjusting to the minors in only his third professional season. Signed out of the Dominican Republic, Florentino looks to have high fantasy upside and be a high priority dynasty league pickup.

From RotoBaller

Philadelphia Phillies shortstop prospect Aidan Miller made his season debut on a rehab assignment with Single-A Clearwater on Saturday. The 22-year-old was 1-for-2 at the plate in his debut with a run scored. Miller returned to action on a rehab assignment for his back injury. The right-handed hitter is the No. 2 prospect in the Phillies system and has a well-rounded game with a 55-grade hit tool, 60-grade power, and 50-grade speed. The Phillies first round pick in the 2023 MLB draft out of a Florida high school, Miller has good size at 6-foot-1 and 205 pounds and made it all the way to Triple-A during the 2025 season. With a chance to get some games under his belt at the end of this season, Miller looks to be a solid dynasty league target. He promises to be one of the up and coming players at the shortstop position.

From RotoBaller

Minnesota Twins prospect Emmanuel Rodriguez is hitting for power in his limited action at Triple-A St. Paul this season. In 45 games at Triple-A, Rodriguez has 11 homers and 31 RBI but is hitting just .252. Rodriguez has battled a bad thumb injury this season which has limited his game time but the power in his bat has shown. The 23-year-old left-handed hitter is the No. 5 prospect in the Twins system and has a 45-grade hit tool with 55-grade power and speed. Rodriguez also has seven stolen bases in his little game time this season. Rodriguez has some work to do on his overall hitting and is a batting average risk for fantasy but his power-speed combination is real. The Twins have already called up top prospects Walker Jenkins and Kaelen Culpepper so they might elect to keep Rodriguez in the minors the rest of this season. but if they do look his way for a promotion he could have some late impact on the fantasy season.

From RotoBaller

Brewers' 2B David Hamilton had three stolen bases and a .400 average in four games this week. Hamilton is owned only in 2.6% of mixed leagues.

Seattle's C Cal Raleigh scored 27.5 fantasy points going 8-for-21 with two home runs and five RBIs in five games this week. Raleigh is owned in 69.8% of mixed leagues.

Rangers' 1B Ezequiel Duran scored 25.5 fantasy points going 6-for-21 with two home runs and four RBIs in six games this week. Duran is owned in 73.5% of mixed leagues.

Twins' C Ryan Jeffers scored 36.0 fantasy points going 6-for-21 with four home runs and 11 RBIs in five games this week. Jeffers is owned in 68.2% of mixed leagues.

Athletics' SS Alika Williams had a slash line of .412/.474/.824 going 7-for-17 with 4 RBIs in five games this week. Williams is owned only in 0.0% of mixed leagues.

Athletics' 2B Jeff McNeil scored 28.5 fantasy points going 9-for-26 with two home runs and five RBIs in six games this week. McNeil is owned only in 16.0% of mixed leagues.

Las Vegas' 2B Zack Gelof scored 36.0 fantasy points going 8-for-25 with three home runs and four RBIs in six games this week. Gelof is owned in 64.0% of mixed leagues.

St. Louis' RF Joshua Baez scored 25.5 fantasy points going 7-for-16 with two home runs and five RBIs in five games this week. Baez is owned in 51.1% of mixed leagues.

Marlins' LF Kyle Stowers scored 25.5 fantasy points going 8-for-20 with three home runs and six RBIs in five games this week. Stowers is owned only in 44.7% of mixed leagues.

Athletics' CF Henry Bolte scored 27.0 fantasy points going 7-for-24 with two home runs and five RBIs in six games this week. Bolte is owned only in 22.3% of mixed leagues.

Boston's C Mickey Gasper scored 27.0 fantasy points going 6-for-22 with three home runs and three RBIs in six games this week. Gasper is owned only in 4.0% of mixed leagues.