Clayton Kershaw leaves start after 2 innings with lower back tightness

— -- LOS ANGELES -- Clayton Kershaw, the? Los Angeles Dodgers?ace who has been at his best the past few weeks, exited Sunday's start after only two innings with what the team announced as tightness on the right side of his lower back.

Kershaw, 29, missed two and a half months with a herniated disk in his lower back last season but hadn't missed a turn this year. The left-hander has been looking like a favorite to claim his fourth Cy Young Award.

Kershaw was checked by manager Dave Roberts and a Dodgers trainer with two outs in the top of the second against the Atlanta Braves. He?stayed in after throwing a couple of practice pitches. Kershaw proceeded to walk?Tyler Flowers and then struck out?Matt Adams?to end the half-inning, and disappeared into the clubhouse. In his 21-pitch outing, he had two strikeouts and one walk and allowed no hits.

Trayce Thompson pinch hit for Kershaw in the bottom of the second, and Ross Stripling took over on the mound in the top of the third.

Kershaw entered his Sunday start leading the majors in wins (15) and ERA (2.07), and he was tied with? Max Scherzer for the National League lead in innings pitched (139 1/3). In his five prior starts, Kershaw had allowed only two earned runs in 36 innings, scattering 22 hits, walking six batters and striking out 51.

Kershaw's potential injury comes amid rumors that the Dodgers are showing interest in Rangers ace Yu Darvish?with a little more than a week left before the non-waiver trade deadline. Los Angeles, with a major-league-leading 67 wins and a plus-173 run differential, is expected to get a sixth starter this week when? Hyun-Jin Ryu?comes off the disabled list.?