From the Orlando Sentinel:

The Magic picked Pietrus this summer to be the team's go-to defender against some of the league's best talent. But with his grasp of the Magic's defensive scheme going slower than expected, there has been an early November surprise.

And it's that reserve guard Keith Bogans has been called on in several key moments ahead of Pietrus, who has easily been more impressive offensively with two 20-point games.