Must-Add Waiver Wire Pickups: Mid-Week Fantasy Baseball Adds for Week 8

May 20, 2026

Dan analyzes 6 must-add fantasy baseball waiver wire pickups, mid-week adds for Week 8 of the 2026 MLB season. Grab these players asap off the waiver wire.

Week 8 of the fantasy baseball season is at its midway point. With the next set of MLB matchups on the horizon, now is a good time to examine the waiver wire in our fantasy baseball leagues to see who can help us this weekend and beyond.

Leading off this week’s list is a 20-year-old shortstop who was called to the show only days ago. From there, we bounce around the rest of the infield to find help wherever you need it. Rounding things out is a reliever turned starter who has been surprisingly effective following the role change.

All players featured in this article will be available in more than 50% of Yahoo leagues. Be sure to check for more waiver wire and other fantasy baseball advice in our MLB hub when you are done reading. For now, here are my favorite Must-Add Waiver Wire Pickups For Week 8 of the fantasy baseball season.

2026 Fantasy Baseball: Mid-Week Waiver Wire Adds

Colt Emerson, SS, Seattle Mariners

On Sunday, the Seattle Mariners called up their top prospect, Colt Emerson. Emerson made his MLB debut the very same day, going 0-for-2 with one walk and one run scored. The next day, the 20-year-old went yard for his first hit in the bigs, with a three-run shot in the eighth inning to extend Seattle’s lead over the Chicago White Sox.

Emerson was the 22nd overall pick of the 2023 draft, when he was still just 17 years old. The young phenom ran roughshod through the minors, inspiring enough confidence within the organization to offer him an eight-year, $95 million contract extension on March 31.

Before his promotion, Emerson had slashed .255/.347/.469 with eight home runs, 26 RBI, and 10 stolen bases in 38 games with Triple-A Tacoma. Now with his parent club, Emerson will shift over from his usual position at shortstop to cover the hot corner. With Brendan Donovan (groin) out of commission for the next few weeks, Emerson will take over as Seattle’s starting third baseman.

Emerson has the tools to be a five-category contributor and ample opportunity to make the most of them. Injury to Donovan aside, general manager Justin Hollander has already claimed that Emerson’s promotion is not meant to be temporary. Talent, time, and impending dual-eligibility make Emerson a must-add.

Matt McLain, 2B, Cincinnati Reds

From one middle infield position, we go to another, to take a look at second baseman Matt McLain of the Cincinnati Reds. McLain has had some pretty rough patches this season, but there have been some flashes of brilliance here and there. As recently as May 5, his batting average rested at .189, but since then, McLain has hit .283 with a .908 OPS and 11 RBI.

McLain has spent most of the position hitting out of the two-hole but was recently busted down to the back third of the lineup. His recent production has pushed him back to the top of the Reds’ order, seeing him lead off on Monday and Tuesday. The results of the hot streak are a reward in themselves, but the returns stand to be greater if he can remain positioned with Cincy’s best bats behind him.

McLain is not a long-term solution at second base, but we can ride the hot streak until it fizzles out. Even if the success at the plate doesn’t last, McLain’s prowess as a base stealer should come into play. He is unlikely to get anywhere against Pedro Pages in the Reds’ upcoming series against the Cardinals, but could be productive next week when Cincinnati faces the Mets and Braves, who have caught just six opponents stealing each in 2026.

Spencer Steer, 1B/OF, Cincinnati Reds

Shifting from the middle infield to the corners, we will give our attention to another Cincinnati Red, first baseman (and outfielder) Spencer Steer. Like McLain, Steer started cold this season but has slowly started turning things around. Steer has a hit or a walk in 20 of the Reds’ last 21 games, hitting .333 with 14 runs and 12 RBI during the stretch.

On the season, he now has seven home runs, 18 RBI, 26 runs scored, three steals, and a .269 batting average. Steer’s batting average has been his biggest drawback in each of the last two seasons, but improvements to his quality of contact make me optimistic that he won’t be a detriment to that category this year.

Steer’s barrel rate is more than twice his career average (15.6% to 7.6%), his pull-air rate (28.3%) is the highest it has ever been, as is his squared-up rate (30.1%). He is driving the ball with purpose, and his resulting .308 BABIP is in line with that of his stellar 2023 and drastically better than the seasons in between.

Fleet of foot, Steer will likely return to double-digit steals by season’s end. While he is not an elite producer, he will make steady contributions in all five categories if he continues at his current pace.

Nolan Arenado, 3B, Arizona Diamondbacks

Across the diamond for those who need help at third base, we have… Nolan Arenado? Left for dead in fantasy drafts this year after submitting a .237/.289/.377 triple-slash and 12 home runs in 2025, Arenado is now up to seven home runs with a .272 batting average in 2026.

Rewinding to the start of Arizona’s series against Texas last week, Arenado has hit .333 with six doubles and seven RBI in his last eight games. He was oddly quiet in a return to Coors Field last weekend, but mashed a grand slam in the first game of a home series against the Giants on Monday.

Curiously, there are no big changes to Arenado’s swing or contact metrics that point to a resurgence. The one that stands out is the frequency at which he hits the ball at an ideal launch angle, which has bounced back to his career norm.

Arenado gets to face the Rockies again, this time in Arizona, in a four-game set that starts on Thursday. Then he goes to San Francisco to face the Giants, whom he has always hit well against, for the early series next week.

Gabriel Moreno, C, Arizona Diamondbacks

Fantasy managers rostering Cal Raleigh (oblique), Drake Baldwin (oblique), and Ryan Jeffers (wrist) have been dealt a blow, with each of those backstops hitting the injured list in the last week. Gabriel Moreno of the Arizona Diamondbacks is here to help you fill out the catcher slot until they can return.

Moreno was injured himself earlier this year with an oblique strain of his own, forcing him out of action for almost three weeks in April. After his return on May 1, Moreno struggled at the plate, collecting just three hits in his first nine games back and seeing his batting average plummet from .275 to .203. His luck changed on May 13.

It was the first of four consecutive multi-hit games for Moreno, during which he hit one home run and logged five runs, five RBI, and (improbably) two stolen bases.

Moreno’s defense will keep him behind the dish on an almost daily basis for the Diamondbacks. As noted above for Arenado, Arizona has some hitter-friendly matchups on deck, with a Thursday game thrown in for added measure. If you need a catcher in a pinch, you could do worse than Moreno.

Ben Brown, SP/RP, Chicago Cubs

Moving on to the pitcher’s mound, we find Ben Brown of the Chicago Cubs. Brown started the season in the bullpen and was briefly a candidate for closing duties when Daniel Palencia was injured. Injuries to the rotation pushed Brown into a starting role, and since the move, he has done well for himself and his team.

Brown’s first two starts lasted four innings each, over which he surrendered zero runs, gave up just one hit and three walks, and registered 10 strikeouts. His most recent start, on May 19, did not go as well. In five innings of work, Brown struck out six but allowed three earned runs on seven hits and two walks.

Brown has done a superb job of inducing groundballs and limiting hard contact, rewarding him (and fantasy managers) with a 2.09 ERA and 0.98 WHIP. He won’t see any more action this week, but should see two starts (@PIT, @STL) in Week 9. Beyond that, Brown continues to have a favorable schedule, with potential starts against the Athletics, Rockies, and Giants down the line.

Brown still has work to do to get stretched out beyond five innings, so he might not be one to count on to add to your wins column. However, he should add a handful of strikeouts to your tally in his starts and help to rein in pitching ratios.

Other Waiver Wire Targets

• Samuel Basallo, BAL
• Bryson Stott, PHI
• Bryce Miller, SEA
• Sam Antonacci, CWS
• Casey Schmitt, SFG
• Anthony Volpe, NYY
• Aaron Ashby, MIL
• Zebby Matthews, MIN

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