Rivals.com named him the seventh-best prospect in the state of Arizona.

In 2008, he was named the 14th-best prospect in the Diamondbacks organization.

He was also named the best prospect in the Arizona League.

Baseball America named him the 5th-best prospect in the Orioles' farm system for the 2009 season.

Baseball America named him the top prospect in the league in a poll of managers.

He was named the 12th top prospect by Baseball America in 2006.

Before the 2009 season, Walden was named the 70th best prospect in baseball.

He was named the 94th best prospect in baseball by Baseball America prior to the 2011 season.

Rivals.com ranked him the 14th best center in his class, and Scout.com named him the 110th overall prospect.

Baseball America also named him the fourth-best prospect in baseball.