5 Undervalued Hitters and Fantasy Baseball Waiver Wire Adds (Week 17) - Players Who Are Underowned

Five fantasy baseball waiver wire pickups, sleepers, and trade targets for Week 17 -- undervalued hitters outperforming their rostership and should be more widely owned.

The 2025 Major League Baseball season is flying by as we're already a week into the second half of the campaign. That means we're inching even closer to the end of the regular season of fantasy baseball, and the playoff push may be heating up in respective leagues.

It's a crucial time for fantasy managers, and the waiver wire becomes especially important. Knowing who's hot and who's not becomes paramount. In Week 17, we're taking a closer look at Wilyer Abreu, Willi Castro, Alec Burleson, Ezequiel Tovar, and Noelvi Marte. While Castro, Burleson, and Tovar have all appeared in this column before, Abreu and Marte have joined the conversation and are ready to make their case for why you should roster them.

Each has shown flashes of greatness this season. Now, it's up to you to determine whether they're worth the roster spot.

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Wilyer Abreu, OF, Boston Red Sox

59% rostered

Entering the series against the Philadelphia Phillies, Abreu had his fourth multi-homer game of the season against the Chicago Cubs on Sunday, tallying eight bases and three RBI, adding a walk. The two home runs brought his total on the season to 20, a new career high. Unfortunately, Phillies pitching stifled Abreu's momentum on Monday, striking him out twice. Still, the Red Sox hope he can have a resurgent second half.

Wilyer Abreu homers AGAIN 🤯 pic.twitter.com/gc7e2pNOxg

— MLB (@MLB) July 20, 2025

Abreu had a torrid start to the season. He began the year with a two-homer game against the Texas Rangers on Opening Day, and slashed .295/.417/.547 with 12 extra-base hits, 21 RBI, 20 walks, and 26 strikeouts through his first 30 games. His production slowed in May, batting .212 with a .687 OPS, walking four times and striking out 20, but he managed seven home runs.

Despite landing on the injured list in June, the 26-year-old slugged .500 and drove in 16 runs during the month.

Now, in July, Abreu has four homers, 10 RBI, and a .897 OPS in 13 games. One thing that's remained fairly consistent is his power, with a .522 expected slugging percentage. He's a pull hitter, with all of his homers coming from that side, and none clearing the opposite field fence.

Abreu averages a 91.4 exit velocity, a 46.9 hard-hit rate, and a 13 percent barrel rate. He could stand to cut down his K rate, striking out 24.2 percent of the time. That said, he's become a potential intriguing name at the deadline as teams search for added power to their lineups.

Willi Castro, 2B/3B/SS/OF, Minnesota Twins

51% rostered

Only three homers away from besting his 2024 home run total (12), Castro is having another productive season in his third year with the Twins. He's batting .257/.347/.431 with 10 home runs, 27 RBI, and 31 walks. While these numbers aren't exactly awe-inspiring, the 28-year-old has been somewhat better than his counting statistics suggest.

Unlike Abreu, Castro had a slow start to the 2025 campaign, batting .192 in April with 11 strikeouts and two extra-base hits.

Willi fast, Willi scored! pic.twitter.com/U6DBvXQPpD

— Minnesota Twins (@Twins) July 20, 2025

He landed on the injured list on April 24 with a right oblique strain, eventually returning to the club on May 5. Since May 14, Castro has had a .852 OPS with nine home runs, eight doubles, and two triples, as well as seven stolen bases, 26 walks, and 56 strikeouts. His underlying stats aren't the most encouraging, either, but he's launching the ball at a desired rate, with his 38.2 percentage ranking in the 83rd percentile.

Castro's ability to draw free passes is also above the MLB average, at 9.8 for the season compared to an 8.4 for the rest of the league.

So, maybe he's not hitting the ball especially hard, but he makes contact at a reasonable rate and has been effective in high-leverage situations. Castro has a .309/.433/.491 batting line with runners in scoring position, with 16 RBI and 10 walks. Additionally, he's seeing lefties well, with a .870 OPS in 80 at-bats against them this year.

Castro's versatility on the diamond makes him a desirable waiver wire option, too.

Alec Burleson, 1B/OF, St. Louis Cardinals

50% rostered

Burleson appeared in Week 13 of this column, highlighting how consistently underrated he has been across the league and how undervalued he is among fantasy managers. He's followed up an impressive June with a solid July, and over his last seven games, he's slashing .350/.480/.500 with a homer, four walks, three strikeouts, and a stolen base.

Overall, the 26-year-old is batting .293 alongside a team-leading .811 OPS. Burleson's 12 home runs and 44 RBI are second on the club, and his 44 strikeouts are ninth, with 29 of his 90 hits going for extra bases this season.

Alec Burleson obliterated this ball. #STLCards pic.twitter.com/DBVwr5zU1A

— Cardinals Dude (@Turn2Dude) July 5, 2025

Advanced metrics support his offensive success this season as well, as he has an expected batting average of .288, which ranks in the 89th percentile in MLB, per Statcast. Burleson's xwOBA of .358 is in the 78th percentile, while his xSLG (.483) and average exit velocity (91.2 mph) are 74th. His strong plate discipline is highlighted by his 15.7 whiff percentage and 13.1 strikeout percentage, which place in the 89th and 90th percentiles, respectively.

Burleson has a 1.4 fWAR on the season to go with a 127 wRC+ and 126 OPS+. That said, he sat out of Tuesday's game due to a right foot contusion after fouling a pitch off it on Monday. While X-rays were negative for the slugger, it's something to monitor moving forward. Should he stay healthy, he should be in store for a fruitful second half as the Cardinals attempt to make a playoff push.

Ezequiel Tovar, SS, Colorado Rockies

47% rostered

Activated from the injured list on July 18, Tovar has already begun to show why he's one of the few Rockies who will likely be untouchable at the upcoming trade deadline. Since being reinstated, he's gone 5-for-15 with a double, a home run, and three RBI, striking out four times. The 23-year-old's value to Colorado is undeniable, but he has already experienced his fair share of injuries throughout his career, especially this season.

Ezequiel Tovar 3-run shot to the fountains for the lead! pic.twitter.com/FqiJSHCbcB

— Talkin’ Baseball (@TalkinBaseball_) July 20, 2025

Tovar initially landed on the injured list in June with a left oblique strain. This was only a few weeks after he returned from a month-long IL stint with a left hip contusion he suffered in April. An already lost and historically bad season for the Rockies has been even worse thanks to his inability to stay healthy. When healthy, though, he's by far Colorado's best offensive player.

He's batting .264 with a .727 OPS and 13 extra-base hits this season, along with 13 RBI, seven walks, and 34 strikeouts. Given that Tovar has been injured for most of the year, it makes sense that his rostered percentage has dropped significantly since the 2025 campaign began.

Fantasy managers may have had to make room for other bats on their injured lists. However, Tovar may be worth picking up again, especially when the Rockies have a homestand, as he's batting .397 at Coors Field, compared to a .163 average on the road.

Noelvi Marte, 3B, Cincinnati Reds

29% rostered

Like Tovar, Marte has dealt with his share of injuries this season, appearing in only 34 games in 2025. A left oblique strain has kept him sidelined for most of the year, but when he has been on the field, he's lived up to the hype that followed him up until his MLB debut in August 2023. Marte was suspended before the 2024 campaign, so overall, he has played a little over 135 games in his career.

Some insurance brought to you by Noelvi Marte@MarteNoelvi pic.twitter.com/RCeYr95FC3

— Cincinnati Reds (@Reds) July 23, 2025

At just 23 years old, he's slashing .282/.341/.504 with six home runs and 26 RBI across 129 plate appearances this season. Marte will soon see time in the outfield in addition to third-base duties. Reds manager Terry Francona said he won't be in right field every day, but will see time there occasionally against lefties.

Marte started the year in Triple-A, and upon his call-up on April 17, he went on a tear, with a .966 OPS, three homers, and 16 RBI in 15 games in April before landing on the IL. Now in his third year in the big leagues, we have yet to see what a full season looks like for him. If it's anything like what we've seen in small sample sizes, then Marte is set up for a bright future in Cincinnati.

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