Hitter Fantasy Baseball Breakouts - Risers to Watch and Waiver Wire Outlooks (Week 21)

August 14, 2026

Jarod's hitter fantasy baseball breakouts, sleepers, and risers to watch for Week 21 of 2026. His list includes waiver wire outlooks and underachieving hitters.

Welcome back to my Fantasy Baseball Breakout Hitters article for Week 21 of the 2026 MLB regular season. The goal of this article is to highlight players who could be getting hot, review current active hitting streaks, and look at recent leaders in batting average, isolated power (ISO), stolen bases, and more.

This week we'll take a look at players like Spencer Jones, Griffin Conine, and Angel Martinez. The focus in this column is on players who have a chance to be available on your waiver wire.

Remember that any time we talk about rostered percentages or positional eligibility, we're referring to Yahoo! leagues. With that in mind, let's dive into potential hitter breakouts for Week 21 of the 2026 MLB season.

Hit Streak Leaders

Data through 8/12

Angel Martinez (eight games) 

Angel Martinez is having a resurgent August, now fully recovered from a foot injury that landed him on the injured list for just over a month through July 24. The 5-foot-11 Dominican posted a 121 wRC+ in the first month of the season, but recorded a 60 wRC+ in the 43 games played through the end of July.

However, in August, the switch-hitter owns a 196 wRC+ through eight games, going 13-for-33 (.394) with five doubles, a home run, 10 RBI, and five runs scored. With an 8.3 percent barrel rate and 12 home runs on the year, more round-trippers and extra-base hits should be in store. The drawback here is that he chases as much as anybody in the majors, which leads to an MLB-worst 2.7 percent walk rate.

That probably makes him an avoid in OBP leagues, but he can put up useful stats in most other mixed leagues. The 24-year-old is available in over 80 percent of leagues, and is eligible at both 2B and OF, adding to his appeal.

Andres Gimenez (seven games)

Andres Gimenez is currently riding a seven-game hit streak, and perhaps that doesn't move the needle for you when you look at his overall numbers and see that he is batting .240 with a 79 wRC+, but looking at career numbers, this could be something sustainable.

The veteran's best two months over the course of his career in terms of average, wOBA, and wRC+ are August and September. For example, the left-handed hitter owns a career .260 average in August and a .270 average in September, but no better than .249 in any other month.

Andrés Giménez gives the @BlueJays an early lead 😤 pic.twitter.com/yNb4T7YkCA

— MLB (@MLB) August 8, 2026

The 5-foot-11 Venezuelan is 10-for-27 (.370) during the hit streak, with two doubles, a home run, seven RBI, four runs scored, and three steals in seven games. If history repeats and the improved average gets him on base more, then more steals could also follow, now with 16 on the season. He's available in over 80 percent of leagues and is eligible at both 2B and SS.

Highest Batting Average Last Seven Days

Data through 8/12

Jonny DeLuca (.467 BA)

Jonny DeLuca got here because of a pair of three-hit performances this week, which included two doubles and a couple of stolen bases. The right-handed hitter doesn't necessarily play every day, though, which can make him somewhat frustrating for fantasy, but in leagues with daily lineup changes, the 5-foot-10 slugger offers a decent batting average (.273) with a little pop (eight home runs) and plenty of stolen base appeal (14 SB; 92nd percentile sprint speed).

Jonny DeLuca (8) GOES YARD 🔥
103.1 mph · 398 ft · 30°
RHP Logan Gilbert · 95 mph four-seam fastball

⚾ TB 1 - SEA 0 • Top 2nd pic.twitter.com/AaC13sMm1F

— PlayPulse HRs (@PlayPulseHRs) August 8, 2026

The former 25th-rounder rapped multiple hits in four of five contests from July 17 to July 24, so this didn't necessarily come out of nowhere either. If he can continue to get on base, then surpassing his previous career high of 16 steals in 2024 seems all but an inevitability.

With decent contact and better-than-average strikeout rates, he'll continue to put the bat on the ball, and while a .273 average doesn't necessarily jump off the page, when you consider league average is around .244, it is plenty useful for fantasy purposes. You can find the 28-year-old in pretty much every league, but he's worth a look, especially if you're desperate for stolen bases.

Highest ISO Last Seven Days

Data through 8/12

Griffin Conine (.526 ISO)

Griffin Conine has been making the case as of late that he should be a mainstay in the Miami lineup, including tallying multiple-hit performances in three of his last four games, which include three home runs. With 13 home runs in all over a period of 54 games, the former second-rounder looks like a solid speculative play for power down the stretch.

GRIFFIN CONINE IS SIZZLING ♨️ pic.twitter.com/EZ0ZcJNICj

— Miami Marlins (@Marlins) August 13, 2026

The 29-year-old has a terrible strikeout rate of 29.7 percent, but it is somewhat offset by a solid 12.0 percent walk rate. The former second-rounder has moved from the middle third in the order to the top third, which should help his RBI chances a bit. The left-handed hitter is available in 80 percent of leagues.

Most Steals Last Seven Days

Data through 8/12

Tim Tawa (four SB)

Tim Tawa is not a burner, possessing a middling 53rd percentile sprint speed, but he's been able to make the most of it on the basepaths lately, recording four steals over the past week. That total accounts for more than half of the six steals he's logged all season to this point, but the surge is enough to make us fantasy managers take notice.

The right-handed hitter's season-long batting average of .232 may make managers take a pass on him, but looking closer, he's hitting .310 in August, which includes a pair of home runs, five RBI, and six runs scored in 11 games. Perhaps that is not sustainable over the rest of the season, but if he can land somewhere in the middle (i.e., .271 AVG) while chipping in some steals along the way, that could be useful.

The 27-year-old is available in over 90 percent of leagues for the taking, and can be deployed at 1B, 2B, and OF in Yahoo! leagues.

xwOBA Leaders Last Seven Days

Data through 8/12

Spencer Jones (.496 xwOBA)

Spencer Jones' strikeout rate always looked like it was going to be a limiting factor, but the power has never been in doubt. Over the past week, the former first-rounder has three hits, but all three went for extra bases (two doubles, one home run). With 12 batted ball events over that stretch, though, more probably should have gone down as hits instead of outs.

SPENCER JONES GAME-TYING DOUBLE! pic.twitter.com/1oI3oRjnah

— Talkin' Yanks (@TalkinYanks) August 13, 2026

The 6-foot-7 slugger produced a 93.5 mph average exit velocity this past week, right near his season average of 94.0 mph, which would rank near the top of the league if qualified. Combined with top-of-the-scale bat speed, some of those batted balls should become hits, more specifically, home runs.

An 11.3 percent walk rate helps to get the Vanderbilt product on base, which should theoretically help him use his 93rd percentile sprint speed, too. So far, he's stolen only five bags in 47 games, but four of five have come since July 29.

The 25-year-old is available in over 80 percent of leagues, but he could be a dual power/speed threat down the stretch and should be considered a solid waiver add in deeper leagues.

xwOBA Laggards Last Seven Days

Data through 8/12

Jacob Young (.326 xwOBA)

Jacob Young has been surprisingly productive over the past week or so, going 10-for-22 (.455) with a pair of doubles, a triple, and a home run in his last seven games, not to mention five RBI, five runs scored, and just one strikeout over that span (two walks).

While all that may sound enticing when scouring the waiver wire, he hasn't hit the ball very hard, coming in at 86.4 mph, which is lower than his season mark of 88.3 mph. He does own 93rd percentile sprint speed, which helps him leg out some infield singles that other players simply cannot do, but there are signs pointing to a slowdown, and his .326 xwOBA compared to a .491 wOBA shows there is a large discrepancy in expected versus actual results.

If you were thinking of riding Young's hot streak, he's available in nearly all leagues, but unless you're hoping to pocket some steals, the 27-year-old is probably best left to the wire.

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