Before you read any further, go to your league, right now, and make sure Nick Kurtz is already rostered. Don't worry, I'll be here awaiting your return.
In his first 65 career major league games, Kurtz, somehow still available in 32.9% of ESPN leagues as of Monday morning, scored 181 fantasy points, a total exceeded by only 55 other hitters during that time. And here's the kicker: That span did not include Kurtz's stunning four-homer, 19-total base, 33-fantasy point performance on Friday, one which gave him a total of 216 fantasy points since his April 23 debut, a total exceeded by only 25 hitters.
To put into perspective what Kurtz did in that game alone, his 33 fantasy points matched the single-game record in baseball history, right there alongside Shohei Ohtani's three-homer, 10-RBI, 17-total base, two-stolen base performance last Sept. 19 that made him the charter member of the 50/50 club. Kurtz is only the second rookie to ever reach the 30-point plateau in a game, joining Fred Lynn (June 18, 1975).
You can read more about why Kurtz must be universally rostered in fantasy leagues here. Now that you've rectified that in your own league, let's get to the other players you'll also want to add.
Matt Shaw, 3B/2B/SS, Chicago Cubs (available in 76.4% of ESPN leagues): Unlike Kurtz, this red-hot rookie is in perhaps the most tenuous position as far as rest-of-year playing time of any player heading into this trade deadline week. Here's the dilemma for the Cubs: Shaw has been one of the hottest hitters in baseball since the All-Star break, his 45 fantasy points during that time tied for sixth-best (behind only Kurtz, Jose Ramirez, Kyle Schwarber, Shea Langeliers and Vladimir Guerrero Jr.), but he has also played the entirety of only six of the Cubs' nine games during that time, not to mention he batted a ghastly .198/.276/.280 in 63 first-half contests, also spending a month's time in Triple-A due to said struggles.
The latter is the reason the Cubs have been linked in trade rumors to available third basemen such as Eugenio Suarez, and there's little question that Suarez would play regularly ahead of Shaw if acquired, likely resulting in another demotion to Triple-A for the rookie. If the Cubs stand pat, however, Shaw's adjustments this month should capture fantasy managers' attention. He's showing much more patience (19% chase rate -- that's percentage of swings at non-strikes -- down from 29% before the break), far more contact in the strike zone (perfect 35-of-35 on swings) and greater quality of contact (40% hard-hit rate, up from 27%). That's encouraging enough to make Shaw worth the pickup today, and if Suarez or another similarly regarded player is brought in to supplant the rookie by Thursday, you can simply then move on from Shaw.
Addison Barger, 3B/OF, Toronto Blue Jays (available in 67.1%): Like Kurtz, Barger is a player who needs to be universally rostered, accounting for both his improved production this season as well as his defensive versatility. Only 39 hitters have scored at least 45 fantasy points while appearing in at least 20 games in each of the past three months (May, June and July); Barger joins Jose Altuve as the only two of them who have made at least 25 appearances at two different defensive positions during that three-month span. Thanks to the winter adjustments he made at the plate, Barger places in the 96th percentile in Statcast's hard hit rate and 85th percentile in Barrel rate, a testament to his massive boost in contact quality.
Joe Boyle, SP, Tampa Bay Rays (available in 93.6%): He'll officially move into the Rays' rotation beginning on Tuesday, taking over the demoted Taj Bradley's spot, and don't underestimate Boyle's massive ceiling. He has filthy stuff, from his 98.3-mph four-seam fastball to his slider and splitter that each have generated better-than-40% whiff rates in his brief major league career thus far. What's more, while Boyle is far from becoming a control specialist, his improvements in that department are substantial, going from what was an 18.7% walk rate between the majors and minors last season to 10.6% while with Triple-A Durham and 8.6% so far with the Rays this year. He'll have his workload closely monitored as a member of the Rays staff, but his immense strikeout potential warrants consideration in any fantasy league.
Rotisserie-style player to add
Seranthony Dominguez, RP, Baltimore Orioles (available in 97.2%): Last Wednesday's announcement that Felix Bautista was dealing with right shoulder discomfort, and Thursday's subsequent IL move for the reliever, coupled with Friday's trade of Gregory Soto to the New York Mets, has left the Orioles bullpen noticeably thin of proven ninth-inning options. Dominguez's experience and raw stuff serves the best fit to close games for so long as Bautista is sidelined, though bear in mind that most anything goes in advance of Thursday's trade deadline with this team. Bautista, and Dominguez himself, are candidates to be moved, but the new opportunity -- temporary or not -- for Dominguez makes him at least worth a stash in any rotisserie league. After all, he has a 3.55 ERA with a 30.1% strikeout rate and is 12-of-16 converting his save chances since joining the Orioles at last year's deadline.
Deeper-league pickups
Angel Martinez, OF/2B, Cleveland Guardians (available in 91.0%): He might not be much of a power hitter, nor an elite speedster, but Martinez does enough in either department to play a sizable role for a Guardians team that has struggled to fill center field all year. He has batted .270/319/.476 with five home runs across his past 37 games, with the past nine coming as either the leadoff or No. 2 hitter.
Spencer Horwitz, 1B/2B, Pittsburgh Pirates (available in 92.5%): His first season in Pittsburgh hasn't gone quite as smoothly as hoped, but Horwitz continues to play a prominent role for a Pirates team that might well roll him out there as its leadoff man and regular first baseman the rest of the way. Fantasy's Week 18 could set him up well for a hot streak. His Pirates are scheduled to face at least four right-handed starters, and they conclude the week with a three-game series at Coors Field.