PHOENIX -- Clayton Kershaw hasn't allowed a hit since last October's National League Championship Series.

Three more hitless innings against the Giants in Tuesday's 4-2 loss made it six over three starts this spring, pretty much silencing concern over last year's back injury. Then he threw another inning in the bullpen.

"To see him work both sides of the plate with his fastball, that was good to see," said manager Dave Roberts, who noticed that Kershaw pitched out of the stretch to the final batter he faced with nobody on base, just for practice. "Even when he's not right from pitch to pitch, he expects perfection. That's the competitor that is Clayton. We all have expectations, but none higher than himself."

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Even Kershaw sounded relatively pleased.

"I feel good physically and feel like the ball is coming out OK, so I think I'm where I need to be," said Kershaw, who walked the first batter he faced on a 3-2 pitch. "Results really don't matter, but I guess it's good to see how hitters react to certain pitches, and if you're not giving up hits, that's a good thing."

Kershaw said that he looks for the way hitters react to his pitches to gauge his effectiveness.

"Just look at their swings, see if they're just missing, if they look comfortable taking good swings," he said. "Sometimes, even if they're not getting hits, if that happens you might need to change some things."

After Kershaw, though, the rotation is still uncertain. Rich Hill starts against the Brewers on Wednesday coming off a rough four-run outing. On Wednesday, Kenta Maeda will pitch a simulated game, which Alex Wood did impressively on Tuesday.

With a day off on Thursday, Julio Urias and Brandon McCarthy will pitch on Friday against Texas. Hyun-Jin Ryu will make his Cactus League debut on Saturday, backed up by Brock Stewart , and on Sunday, Kershaw and Wood will pitch.

Urias threw an eye-popping bullpen session on Tuesday. Although management hinted at leaving him behind in extended spring training to conserve innings, that talk has been silenced.

With Scott Kazmir (hip tightness) unsure about his next start, the final rotation spot could come down to McCarthy, Wood or Ryu; all three have dealt with operations in the past two seasons. There doesn't appear to be room in the rotation for Stewart, or for Thomas Stripling , who seems more in play as a multiple-innings reliever.

Ken Gurnick is a reporter for MLB.com.