They also say, in short, that Harper is a big jerk.
It seems unfair to label a still-developing teenager as such, but that's what Kevin Goldstein wrote in a post for Baseball Prospectus.
Regardless, Harper's skills and performance at a junior college in Nevada are all-but ensuring that the Washington Nationals will take him with the top pick in the June draft.
But will any of the opinions about his attitude give the Nats pause? And should they?
Here are some of the damning details Goldstein relays:
The Makeup: This should not be underrated. It's impossible to find any talent evaluator who isn't blown away by Harper's ability on the field, but it's equally difficult to find one who doesn't genuinely dislike the kid.
One scout called him among the worst amateur players he's ever seen from a makeup standpoint, with top-of-the-scale arrogance, a disturbingly large sense of entitlement, and on-field behavior that includes taunting opponents.
"He's just a bad, bad guy," said one front-office official. "He's basically the anti-Joe Mauer."
That's harsh. But, Harper is the one — after being enabled by his mom and dad — who wanted to grow up so fast that he traded the final two years of high school for a GED. He wants to get to the pros yesterday. Sure, he's still a kid, but he's also opened himself to all kinds of nastiness.
Many already have chimed in about whether Harper being a jerk — if that's what he is — "matters." The prevailing opinion seems to be that it doesn't, and won't, in the future.
After all, look at some of the charmers who have played major league baseball.
• Albert Belle scared the bejeezus out of people (some on his own team) before he even stepped into the batter's box.
• Pete Rose (who happens to be one of Harper's idols) rubbed others the wrong way all of the time.
• Some wonder if Ty Cobb was a sociopath.
Yet, all were great players.
Never having met Harper, I can't give an informed opinion about his personality. But after watching this ESPN feature on him again, I wonder if he's some kind of misunderstood genius.
His dad talks about a kid who was "bored" with high school — in the classroom, on the baseball field — and is looking for a challenge. That can manifest itself in weak social skills, which can make one appear to have a bad attitude.
Simply being a surly sourpuss might not be the red flag we should be concerned about, either. Harper's story also brings back the tale of Todd Marinovich. He was "groomed" by his dad to be the prototypical NFL quarterback, and flopped.
Harper could be headed for burnout status.
Or, maybe he is "Baseball's Chosen One" as Sports Illustrated declared last year. The kid can hit a baseball 550 feet and throw one 96 mph. Those are the attributes Harper is banking on.