"The lessons learned on defense last season weren't visible as much in what Justin Upton did. It was more in what he didn't do. He didn't try to throw out every runner on every play.

Lost amid what Upton called a "rough" season offensively were the major strides he made defensively in right field.

"I cut down on the errors and made smarter plays," Upton said. "Obviously, the errors were still there, but from the past I've made some improvements."

Upton went from a combined 23 errors in 2008 and 2009 to just four last season. He merged his tremendous range and strong arm with sure-handedness and good decision-making.

His manager, Kirk Gibson, called it a "huge improvement," and multiple defensive metrics took notice, as well, ranking him in the top five in the majors among right fielders.

"It was more of knowing where to go with the ball and making smarter decisions, not trying to throw everyone out," Upton said. "You have very few chances to throw guys out and the more you watch video of guys playing the outfield, you realize how tough it is to throw someone out. Making the smart play is usually the right way to go."

Gibson sees room for Upton to further refine his defense, specifically when it comes to better understanding the pace of the game. As an example, he drew a distinction between rushing and hustling, saying few situations call for a defender to rush.

"If you sprint to the ball, break it down, get your footwork right and come up, then you make it easier on yourself," Gibson said. "The reality of it is if you sprint to it the third-base coach is probably going to shut the runner down. He has those abilities and he's starting to understand that.""