A quick look at some of the top prospects under the age of 22. This list will not include Bryce Haper or Mike Trout. This list only consists of players that are still considered prospects despite a handful of them already seeing time in the big leagues.
 

Top 22 Prospects under the age of 22
1. Manny Machado BAL SS
2. Julio Teheran ATL SP
3. Shelby Miller STL SP
4. Jameson Taillon PIT SP
5. Gerrit Cole PIT SP
6. Jurickson Profar TEX SS
7. Trevor Bauer ARI SP
8. Manny Banuelos NYY SP
9. Jacob Turner DET SP
10. Wil Myers KC OF
11. Dylan Bundy BAL SP
12. Tyler Skaggs ARI SP
13. Bubba Starling KC OF
14. Miguel Sano MIN 3B
15. Nolan Arenado COL 3B 
16. Taijuan Walker SEA SP
17. Jonathan Singleton HOU 1B
18. Martin Perez TEX SP
19. Carlos Martinez STL SP
20. Christian Yelich MIA OF
21. Billy Hamilton CIN SS
22. Francisco Lindor CLE SS
 

 
#1 Manny Machado BAL SS
I have long been a fan of the O's top prospect. I see Machado as a young A-Rod type player; someone who is built like a corner infielder but quick enough with his hands to play a premium defensive position. I expect him to be in the big leagues within the next year (or sooner if J.J. Hardy continues to hit under .240). Machado is someone who should challenge for 20 plus home runs a year and offer above average speed both on the base paths and in the field. An eventual move to third may occur but for now the 20 year old is on top of my list as a shortstop.

 
#4 Jameson Taillon PIT SP
He can touch the upper 90's with his heater, he has two plus breaking pitches (curve and slider) to go along with a developing changeup. He is young and still developing but the 6'6" righty will be the eventual Ace of the Pirates.
 
 

 
#14 Miguel Sano MIN 3B
Sano is the best power hitter you've never heard of. I have been comparing his power potential to Adam Dunn for the past year or so. The 6'3" 195 pound power hitter currently has a .265 ISO power rate in single A for the Twins. I'm expecting a call up around the 2014 All Star break.

 
#20 Christian Yelich MIA OF
Yelich is still developing but the 20 year old does posses great raw talent. He can hit for a high average with decent power from the left side. He shows great base stealing instincts and is improving in the field. The Marlins are a team in transition but once they settle in, Yelich will be a nice addition to the middle of a potent offense. I'd say he's less than one year away from being called up.