LOS ANGELES — Clayton Kershaw is headed to the disabled list for the second straight summer because of a back injury.

A year after missing 21/2 months with a herniated disk in his lower back, Kershaw was pulled from a start Sunday against Atlanta because of lower back tightness. The Los Angeles Dodgers’ ace exited after two innings in a 5-4, 10-inning victory.

It leaves baseball’s top team without its best pitcher. The Dodgers lead the majors with a 68-31 record and are atop the NL West standings by 10 games.

Kershaw saw a back specialist Sunday evening for tests, and the initial prognosis was he would miss 4 to 6 weeks, according to Ken Rosenthal of Fox Sports.

Kershaw is 15-2 with a 2.04 ERA. The Dodgers are 19-2 when he starts this season, including winning their last 15 games.

Manager Dave Roberts declined to speculate on the severity of Kershaw’s injury or how long the left-hander could be out.

Kershaw said he got hurt while taking warm-up throws before the second inning after retiring the side on eight pitches in the first.

ROYALS-PADRES TRADE: The contending Kansas City Royals acquired three pitchers from San Diego, getting starter Trevor Cahill, closer Brandon Maurer and reliever Ryan Buchter.

The Royals sent pitchers Matt Strahm and Travis Wood, minor league infielder Esteury Ruiz and cash to the Padres.

Cahill was 4-3 with a 3.69 ERA in 11 starts for the Padres. Maurer is 20 for 23 on save tries with a 5.72 ERA.

TWINS-BRAVES TRADE: Hoping to bolster its rotation for a playoff run, Minnesota acquired veteran left-handed pitcher Jaime Garcia, catcher Anthony Recker and cash considerations from Atlanta in exchange for minor league right-hander Huascar Ynoa.

The 31-year-old Garcia is 66-52 with a 3.65 ERA and 808 strikeouts in 176 appearances, mostly with St. Louis.

RANGERS: Starting pitcher Tyson Ross was placed on the 10-day disabled list because of a blister on his right index finger.

METS: New York placed pitcher Zack Wheeler on the 10-day disabled list because of a stress reaction in his right arm. The team didn’t provide a timetable for Wheeler’s return. He was on the DL last month with biceps tendinitis and has struggled in four starts since his return.