Look, a few guys just aren't falling. Kris Bryant is a Top 3 pick. Mark Appel is basically a lock to go Top 5. Jonathan Gray is also out of the question. Here are the unlikely, but possible guys who could drop.
Clint Frazier is a near lock for the Top 10, but he isn't without flaws that could drop him. First off he's under six feet tall, which is sub-optimal, but as a center fielder, not a deal breaker. While he has probably the fastest bat in the draft, he's been pretty bad at pitch recognition. He has 5 tool talent and could end up being McCutchen or Trout. I generally think pitch recognition is a bit more of an innate skill, so I'd bet on him being more like Jeff Francour. But 5 tool players are rare, and even rarer in the middle of the round and the Phillies lobve grabbing athletic guys and hoping to teach them to play.
Austin Meadows is from the same area as Frazier and goes to the other High School in town. Meadows is 4 inches taller and shows much better patience as a hitter with a 2:1 K:BB ratio. His flaw is that his arm is kind of subpar for Center and may force him to Left decreasing his value. Short of that he's got plus power potential, plus speed, above average ability to hit and is good enough in Center that he can likely be a plus defender in Left.
Kohl Stewart is a Right Handed flamethrower with a wicked slider and developing curve and changeup. He's a legitmate QB prospect as well with a commitment to play QB and Baseball at Texas A&M. If he isn't a top 10 pick, does he go on to College? It's certainly a strong possibility. Some scouting reports seem to list him as better than Appel or Gray and he'd be the top Pitcher picked if he was in college instead of High School. If he drops, he'd be a steal... if he signs.
Trey Ball is a Left Handed Pitcher from Indiana. He's big at 6'5", but quite lanky. You can project that he probably has the frame to add 20 pounds. His fastball currently reaches mid-90's, but works mostly in the low to mid-90's. He has 3 potential plus pitches with his Fastball, Curve and Change. His Change seems pretty advanced for a High Schooler, but his fastball is just short of being truely a plus pitch with some arm side movement, but not quite the late break teams might prefer.
Trey Ball is also a Right Fielder with a plus arm and hitting skills that Jonathan Mayo compared to Shawn Green. He played with a wood bat this year, apparently to show scouts that he can hit well enough and isn't just putting up Tecmo stats with the aluminum bats. His numbers are down some, but should he not make it as a Pitcher, it's not crazy to think he could still make it as an Outfielder. His ceiling is higher on the mound though.
Ryne Stanek is a 22 year old Righty from Arkansas. He was projected as a First Rounder back in 2010, but slipped to the Third round (proof that it's not crazy to dream about some great names in the middle of the First or even middles of the Second round) and went to College. He's a 6'4 guy with a lean build who pitches in the low to mid 90's. All of his pitches are roughly league average stuff. He's likely to move quickly through the minors, but his ceiling is probably a mid rotation guy _#3, outside chance if he improves his command to be a #2).
D.J. Peterson has been all over rankings. I've seen him in the back of the Top 10 and down in the low teens. He could very well be available at the Phillies pick. He's currently a Third Baseman for the U of New Mexico, but he's likely a First baseman in the pros. The rub is that he doesn't have great power potential. He's probably a Casey Kotchman/James Loney type First Baseman. He's been strongly linked to both the Marlins at 6 overall (he'll be cheaper and he can be in the Majors pretty quickly for team that kind of stinks) and the Pirates at 14 (That one is pretty strong, I've seen a few guys report that one). Personally I don't want him, and don't be fooled by his college power. He plays in the College Equivalent of the California League and his home stadium is essentially Coors Field, sans the humidor.