As they constructed their 25-man roster this offseason, the White Sox stressed run prevention as a theme.

Great pitching and defense would help them overcome the loss of significant run producers in departed free agents A.J. Pierzynski and Kevin Youkilis.

Thus far, the White Sox defense hasn’t lived up to the standard set forth by management and the coaching staff.

Another error and more awful offense did in the White Sox chances on Monday night in a 3-2 loss to the Cleveland Indians in front of 14,590 at U.S. Cellular Field. Matt Thornton made the costly mistake with an errant pickoff throw in the top of the eighth inning and Adsrubal Cabrera made him pay with a two-out, two-run, go-ahead single. The White Sox have now lost four in a row and 10th of their last 13 games.

“You keep shooting yourself in the foot and you give major league teams opportunities, they’re going to take advantage of them,” White Sox manager Robin Ventura said. “Until we clean it up, you’re going to lose games. It’s that simple.”

Last season, the White Sox committed a major-league low 70 errors and finished with a .988 fielding percentage, tied for the best in the majors.

Their top-notch defense also limited the amount of unearned runs allowed by their pitchers to an Major League Baseball-low 30, nine fewer than the second-place Toronto Blue Jays.

But when Thornton’s pickoff attempt to second base skipped through the legs of runner Drew Stubbs and into center field the White Sox produced their 13th error in 19 games. The unearned run allowed is also the team’s eighth, which puts them on pace for 111 errors and 68 unearned runs.