Yu Darvish’s full head of short dark hair isn’t the only difference with the Texas Rangers’ Japanese pitching sensation of this spring and last spring.

The most noticeable and significant distinction, he said, is a new level of confidence that comes with being more comfortable than the green rookie with long, dyed locks in a foreign land facing unattainable expectations for a first-year pitcher in the big leagues.

“There is a big difference between last year and this year,” Darvish said. “I feel really relaxed … very comfortable.”

Darvish breezed through four innings, allowing no runs and striking out seven during a 12-1 victory in an international baseball friendly against an outmanned Mexico City Red Devils outfit.

The Rangers will get more of a feel for how the right-hander’s new mental state plays through the ups and downs of a long season when he makes his first regular-season start on Tuesday at Houston.

On Thursday, Darvish threw 52 pitches — 42 for strikes —and allowed only two base runners in 14 hitters faced, including Ben Broussard, who struck out on a split-fingered fastball in the second but reached on a wild pitch that catcher A.J. Pierzynski couldn’t handle.

For the spring, Darvish finished 1-1 with a 1.52 ERA and 22 strikeouts and three walks in 17 2/3 innings. Opposing batters hit .138 off him in five outings.

His performance in the Cactus League, plus Thursday’s game, was a continuation of a strong finish to 2012 when he went 3-0 with a 2.21 ERA in September.