The Orioles have two of baseball's top 24 prospects, according to MLB.com.
Britton, who turned 23 on Dec. 22, went 10-7 with a 2.70 ERA in 26 starts last year between Double-A Bowie and Triple-A Norfolk. The lefty, who was added to the O's 40-man roster in November, gave up two earned runs or fewer in 21 of 26 starts.
He was named the 2010 O's minor league pitcher of the year. A third-round pick in 2006, Britton was the 2009 Carolina League pitcher of the year.
Machado was the third overall pick in the last summer's draft and signed for a $5.25 million bonus.
Late last year, the 18-year-old, right-handed hitter got into nine games in the minors and hit .306-1-5. He batted .345 in seven games with Single-A Aberdeen.
More than 20 scouts were polled to produce the list and a player must still have rookie eligibility to qualify for this list. Brian Matusz was listed as fifth on the list last year.
Coming soon: More from a recent interview with Britton, talking about his offseason workouts and his hopes to make the O's this season.