Fantasy Baseball Waiver Wire: Week of August 17

It’s getting late in the fantasy baseball season. With just over a month left to go, head-to-head leagues are approaching the playoffs, and rotisserie league standings are sorting themselves out.

If your team is still in contention, each day is an opportunity. If you play in daily leagues, check your lineups each afternoon to swap out hitters that aren’t playing that day. In weekly leagues, keep scouring the wire for two-start pitchers and hitters that are gradually earning more playing time. Sometimes one run or one strikeout can make or break a season.

Below are five notable players, most of whom are owned in less than 25% of ESPN leagues, that have the potential to make an impact in the final weeks of the season.

Ownership percentages via ESPN. All stats as of games on August 17th.

Joshua Baez, STL OF (42% owned)

2026 Stats (AAA): 461 PA, .256/.328/.573, 34 HR, 21 SB, 121 wRC+

Following what may have been the greatest debut in MLB history, Baez’s ownership rate soared to 42% in just a couple of days. Typically, ownership is capped at 25% for our fantasy waiver wire pieces, but Baez’s torrid start was too notable to exclude.

While he’s not currently a member of Just Baseball’s top 100 prospects list, Baez has top-100 upside. He projects to be a power-over-hit guy (as you may have noticed by his three-homer debut), and those concerns regarding his hit tool are why he isn’t universally seen as an immediate star.

The fantasy intrigue with Baez lies in his bat speed. In two games at the major league level thus far, Baez has posted an average bat speed of 79.8 mph, instantly placing him among the game’s elite. It’s clear that Baez has the potential to hit for a lot of power, though it remains to be seen if he can adjust to consistently make contact against major league pitching.

Christian Scott, NYM SP (14% owned)

2026 Stats: 84.2 IP. 3.51 ERA, 1.29 WHIP, 19.1% K-BB%, 3.61 SIERA

It’s not easy to find starting pitching on the wire right now. I prioritize mentioning new pitchers each week, but there were no pitchers owned in less than 25% of ESPN leagues that I could recommend more than Scott or Walbert Urena, both of whom I have recently mentioned in my waiver pieces.

Scott isn’t a bona fide ace just yet, but he’s racking up a lot of strikeouts and possesses four above-average pitches, per Stuff+. He’s struggled to work deep into games for much of the season, but the right-hander lasted a season-high 6.1 innings in his most recent start against the Nationals. Even if Scott can’t make it through the fifth inning, he’s been good for five to seven strikeouts in each outing.

Scott’s next start will come this weekend in Chicago against the White Sox. This isn’t an overly favorable matchup, but Scott should be deployed whenever he isn’t pitching in Denver or Sacramento.

Eduardo Valencia, DET 1B, C (8% owned)

2026 Stats: 56 PA, .389/.411/.833, 6 HR, 0 SB, 246 wRC+

Valencia likely wasn’t on the radar of most non-Tigers fans, but his emergence has been a welcome surprise to fantasy managers in deeper leagues. The 26-year-old backstop has made a big impact in a small major league sample.

A key reason for Valencia’s success in the minor leagues was his plate skills, striking out just under 20% of the time in each of the past two seasons while walking between 8-10%. He’s been more aggressive so far in the majors, striking out at a 26.8% clip early on and drawing just one walk.

Though he’s still tweaking his approach, Valencia has been mashing baseballs when he’s gotten the bat to them. His 25.6% barrel rate is absurd, and Valencia’s 73.4-mph bat speed shows that there’s reason to believe he can continue to hit for power. In two-catcher leagues or leagues of 14 teams or greater, Valencia could be of use.

Kodai Senga, NYM SP, RP (7% owned)

2026 Stats: 49.2 IP, 7.79 ERA, 1.65 WHIP, 11.4% K-BB%, 4.53 SIERA

Normally, player statistics before the written description are supposed to be useful to you, the reader. In this case, I want you to completely ignore them. These stats describe Senga: the unsuccessful starter; I will be pitching Senga to you as the potential impact closer.

Functioning as a one-inning reliever this month, Senga has thrown five shutout innings. Over that span, he struck out seven, allowing just one hit and one walk. He struggled with his command as a starter, but in the bullpen, Senga has been able to let his 4-seam/forkball combo eat.

Senga has quickly risen to fantasy relevance due to Devin Williams’ shoulder injury, which landed him on the IL last Monday. In Williams’ stead, Senga earned three saves last week. Until Williams returns, Senga is a viable closer in all formats. I added him in a 10-team league to replace Williams.

Abimelec Ortiz, WSH 1B, OF (5% owned)

2026 Stats: 41 PA, .300/.317/.700, 5 HR, 0 SB, 173 wRC+

For much of the Nationals’ season, Curtis Mead and Luis Garcia Jr. occupied the corner infield spots. Now that both of them were moved at the deadline, new players — like Ortiz — are getting a chance to stake their claim to next season’s roster. Ortiz, who was acquired from the Texas Rangers in the MacKenzie Gore trade this offseason, has been making the most of his newly available playing time in D.C.

Early readings show that Ortiz’s 76.3-mph bat speed is well above league average, which should allow him to hit for power. The 24-year-old lefty had hit 18 Triple-A homers in 85 games this season, following his 25-homer campaign in 2025 at the minor leagues’ two highest levels. Don’t expect any steals from Ortiz, however, as his speed rates as a 20 on the 20-80 scouting scale, per FanGraphs.

An underrated aspect of player intrigue is playing-time availability, and Ortiz should be getting plenty of it to finish this season. I added Ortiz for two percent of my yearly free agency budget in a 15-team league this week, but he’s also viable in 12-team leagues.