CHICAGO - Still grasping for the feel on his offspeed pitches, right-hander Yu Darvish has pushed back the start of his rehab assignment.

But, Rangers pitching coach Doug Brocail said, it isn't a setback.

Darvish threw secondary pitches for more than half of his 47-pitch live batting practice session Thursday. Afterward, he said he wanted to "sleep on a decision" about whether he would begin a rehab assignment at Double-A Frisco or take another live batting practice session.

"I felt like he was strong," Brocail said. "But I don't think he was as happy with his offspeed as he'd like. He has his fastball, cutter and slider, but I don't think he's sure about the changeup and his curve balls."

The amended plan calls for Darvish to throw a 60-pitch batting practice session on Tuesday, then go to Frisco on May 1. Brocail said the extra batting practice session does not constitute a setback because the Rangers will ramp up the pitch count from 45 to 60. He will then back down to 45 pitches for his first rehab assignment.

The plan does, however, rule out any chance that Darvish would return by May 11 to finish a homestand. The new earliest-possible-date is May 16 at Oakland if Darvish throws 45,60 and 75 pitches in his first three rehab starts.

"Once he gets to five innings and 75 pitches, he could either go to the majors and throw 90 pitches or do that in the minors," Brocail said. "It really does not matter which way he wants to go with [Sunday's session]. This just gives him more chance to repeat his pitches. If he says he's ready to go [after 75 pitches[, then we will let him run. If he needs another start, he can take that, too."