"Very good, and I don't even think he even had his best fastball command today," D-backs manager Chip Hale said of Greinke. "Used his offspeed stuff really well."
Rogers: D-backs riding 'Zack Greinke effect'
Things were not as positive for Rangers starter Chi Chi Gonzalez, who is battling to win the No. 5 spot in the Texas rotation.
Gonzalez allowed seven runs on eight hits in 3 1/3 innings. His first two frames were scoreless before giving up five runs in the third inning and two more in the fourth. Castillo and Brandon Drury hit back-to-back home runs off him in the third.
Gonzalez said he left some sinkers in the middle of the plate, but he also did not strike out a batter. He has one strikeout in 81/3 innings in Cactus League and "B" games.
Brocail has simple message for Rangers pitchers
Gonzalez said he needs better bite on his slider. That's his strikeout pitch and it hasn't been effective so far this spring.
"It's been up in the zone, not down in the zone," Gonzalez said. "I'm focusing too much on throwing it for strikes and not getting it down in the zone. I need some punchouts. I haven't gotten any yet. That will help me out."
The homer was the third of the spring for Castillo, who has 12 hits this spring, 11 of which have gone for extra bases. Kevin Cron added a two-run shot in the seventh to increase the lead to 9-0.
Michael De Leon knocked in the Rangers' lone run with a double in the eighth, but the D-backs also tacked on a pair of additional runs in the eighth.
The win was Arizona's 10th in its last 11 games.
Rangers outfielder Shin-Soo Choo was back in the lineup after being sidelined for a week with tightness in his back. He went 1-for-3.
Up next for Rangers: Right-hander Nick Martinez pitches for the Rangers against the Angels at 3:05 p.m. CT, live on MLB.TV and Gameday Audio, on Sunday in Surprise, Ariz. Martinez is trying to win a spot as the fifth starter. Closer Shawn Tolleson and relievers Andrew Faulkner and Tony Barnette are also scheduled to pitch. Cole Hamels will pitch in a Minor League game.
Up next for D-backs: Shelby Miller gets the starting nod for the D-backs on Sunday at 1:05 p.m. MST, live on Gameday Audio, against the Reds in Goodyear, Ariz. It will be the right-hander's third Cactus League appearance. His last outing came in a camp game during last Tuesday's off-day.