Young infielders making rookie defensive mistakes

SEATTLE -- Seattle's young infield was responsible for much of the team's success when the Mariners went 15-10 in July. Rookies Brad Miller at shortstop and Nick Franklin at second base combined to significantly increase Seattle's offensive production as the first and second hitters in the lineup, respectively. Third baseman Kyle Seager and first baseman Justin Smoak provided power behind the rookies' speed.

But that youthful exuberance has come with a price of late, as the infield has been responsible for an inordinate number of fielding mistakes. Over the past 11 games, Seattle has committed 12 errors. The rookies have also tried to do too much at times, throwing to the wrong base and costing Seattle runs, even if an error wasn't recorded.

"The veterans know right away that they've made a mistake and most of the time they don't make the mistakes," acting manager Robby Thompson said. "In the case of the guys up the middle, they're learning on the job. They're learning and getting topped off at the big league level. It's a different ballgame playing up here every day than it is in [Triple-A] Tacoma or Double-A [Jackson]."