This is Part 1 of a series featuring 12 rookie sleepers who are being undervalued in dynasty drafts. To keep things fair, and include intel for those in our deepest dynasty leagues, I’ve broken each position into three categories: Day 2 picks, Day 3 picks, and UDFA.

Day 2 Day 1: J.J. McCarthy (Michigan) - Vikings

6024/219 | RAS: N/A | Player comparison: Rich Gannon

What? You didn’t really think I was going to write a rookie column and leave out my boy JJ, did you?! No, McCarthy wasn’t taken on Day 2 – he went 10th overall – but no quarterback went in Rounds 2 or 3 (nor 4!) this year, so McCarthy, QB5 in April, is being grandfathered into this category.

The QB3 in my pre-draft rankings, McCarthy found the best situation of any quarterback drafted. The Vikings have: a skilled playcaller in HC Kevin O’Connell, one of the NFL’s best receiving corps, a star receiving tight end, and a pair of stud bookend tackles.

Last year, McCarthy won a national title as a 20-year-old third-year junior. He’s a good athlete – with the sixth-fastest 3-cone at the NFL Combine and a reported 4.48 40 at Michigan. And he has a big-league arm – with a 61 mph max-velocity throw at the Combine that fell one mph under the record. Those things work in conjunction with one another on the field.

McCarthy’s 72.3% completion percentage in 2023 – No. 5 in the FBS in catchable throw rate – only dropped to 71.4% while scrambling. He has the lateral agility and acceleration to get out of sticky situations, and he takes his mechanics with him on the move. McCarthy’s improvisation could be special at the next level.

McCarthy mercilessly attacks the middle of the field — a key aspect of O’Connell’s offense. Last year, McCarthy had the most completions in the intermediate range over the middle among the top quarterbacks in this draft class, finishing with an 85.6% adjusted completion percentage and 91.2 passing grade between the hashes.

During the latter half of 2023, in a gauntlet of murderer’s row defenses during Michigan’s run to the title, McCarthy became increasingly comfortable moving to his second and third reads. He still needs to improve in this area, but the signs of progression are encouraging.

McCarthy also could stand to modulate his touch on certain throws. He will improve as a passer if he trades velocity for trajectory or touch on throws that call for them. Last year, he managed to rank No. 5 in the FBS in catchable throw rate despite finishing No. 48 outside the numbers. When he’s off, it’s due to his tendency on those throws to take an exaggerated lead step and then swing his upper body on the follow-through. 

The fantasy community is underselling the value McCarthy’s legs will provide. His prerogative is to use his athleticism to evade pressure and scan down the field for options. But McCarthy is dangerous when he tucks, capable of stealing yards quickly. And he could score a lot of NFL touchdowns around the goal line.

Current expectations have Sam Darnold starting to begin the season, with McCarthy learning behind him. I think McCarthy plays sooner than expected. In KOC’s offense, throwing to Justin Jefferson and company, McCarthy has the potential to be a fantasy star. 

Day 3: Spencer Rattler (South Carolina) - Saints

6002/211 | RAS: 4.13 | Player comparison: Jeff Blake

The No. 11 overall prospect in his recruiting class, Rattler was the first hand-picked high school prospect to start for former Oklahoma HC Lincoln Riley. As a redshirt freshman in 2020, Rattler ranked No. 4 with a 92.5 PFF grade. He led the FBS in PFF big-time throws under pressure and passing grade out of structure. 

Following that season, Rattler was seen as a potential No. 1 overall pick. But the next year, in 2021, Rattler was benched for Caleb Williams. Rattler never reached the same heights at South Carolina. But there’s still dormant talent to untap here. 

Rattler prefers to be in shotgun with his receivers spread out. A short, aggressive pocket passer with a snappy arm, he likes to move around to give himself better vantage points to throw. This wasn’t a good fit behind South Carolina’s poor offensive line that ranked outside the top-100 in PFF pass-blocking grade each year he was there. 

Rattler struggled to adapt his game during the first 10 games of 2022, but his work since that time in a poor situation was yeoman. He rips through progressions and is poised with heat in his face. Rattler excels at testing NFL money zones, 10-plus yards down the field between the hashes. 

Rattler remains frustratingly inconsistent due to his live-by-the-sword, die-by-the-sword aggression. But getting him away from South Carolina’s shoddy offensive line is going to help his game. Rattler could quickly challenge Jake Haener for QB2 duties behind Derek Carr.

UDFA: John Rhys Plumlee (Central Florida) - Steelers

6000/200 | RAS: 8.81 | Player comparison: Trace McSorley

The well is admittedly dry here, but Rhys Plumlee has a multi-faceted skillset that could keep him on a roster.

In college, Rhys Plumlee also played center field on the baseball team. Earlier in his career at Ole Miss, he started at QB in OC Rich Rodriguez’s system. When Ole Miss changed offensive schemes, Rhys Plumlee played slot WR, with the Rebels also making heavy use of him on gadget plays.

Rhys Plumlee is undersized, and his accuracy comes and goes. But he has above-average arm strength for his size, and loves to test defenses down the field. He’s also, of course, a skilled scrambler. Rhys Plumlee ran a 4.51 during the pre-draft process and finished as an 88th-percentile athlete at the position.

Rhys Plumlee’s diverse skillset gives him two developmental bullets to make the NFL. If he fails at quarterback, he’ll try as a slot WR who adds value on trick plays.

He’s only rosterable in the deepest of dynasty leagues. But those who play in a league like that could do worse with a spot at the end of their taxi squad.