Dodgers' Roberts: Kimbrel's 'stuff is starting to slide'

Los Angeles Dodgers manager Dave Roberts feels uneasy about veteran closer Craig Kimbrel after another rough outing against the Arizona Diamondbacks on Thursday.

"You can't hit the leadoff hitter with a breaking ball," Roberts said postgame, according to Juan Toribio of MLB.com. "I think the stuff is starting to slide a little bit, fastball velocity. I've just got to continue to look at this. We've got to have our best guys at the back end."

Kimbrel hit a batter and allowed a go-ahead home run in the ninth inning before the Dodgers won the game in dramatic fashion. He owns a 4.14 ERA with 1.34 WHIP and is 22-for-27 in save opportunities over 57 appearances (54 1/3 innings) in his first campaign with Los Angeles. The eight-time All-Star's 10.8 K/9 is the worst mark of his 13-year run in the majors.

Roberts acknowledged there's a very small margin for error with the playoffs starting in October.

"This is a point in time where performance matters," Roberts said. "We need our best."

Kimbrel, who's widely considered one of the best closers in MLB history, owns a career 2.33 ERA with 394 saves.