The right-hander woke up with neck stiffness and was scratched from his start against the Twins on Tuesday night at Target Field. Right-hander Scott Baker took his place.
Darvish began the season on the disabled list because of stiffness in his neck.
"He said it's not as bad as Spring Training," general manager Jon Daniels said. "We're playing it on the safe side for a variety of reasons. It's the second time he's had it, and with all the injuries we've had, we're playing it cautious."
Baker was supposed to be in the bullpen as the long reliever, but the Rangers are not going to make a roster move. They will have to make one on Wednesday because they are planning to activate Joe Saunders off the DL to start against the Twins.
At that point, the Rangers will have to make a call on Darvish or go shorthanded in another area. Darvish's next start would fall on Sunday against the Nationals in Washington. Darvish would have to bat in that game because there is no designated hitter, but manager Ron Washington insisted that would not keep Darvish from starting if he is physically ready to go.
"If he can pitch, I want him to pitch," Washington said.
Darvish is 4-2 with a 2.35 ERA in nine starts. He is fourth in the American League in ERA and seventh with 71 strikeouts. Opponents are hitting .215 off Darvish, the sixth-lowest average in the league.
T.R. Sullivan is a reporter for MLB.com. Read his blog, Postcards from Elysian Fields, and follow him on Twitter @Sullivan_Ranger. This story was not subject to the approval of Major League Baseball or its clubs.