SCOTTSDALE, Ariz. -- D-backs right-hander Zack Greinke threw to hitters Friday as part of a 40-pitch work day under rainy conditions.

¡°Everything felt good, went good,¡± Greinke said.

The hitters didn¡¯t swing against Greinke because of the rain, and the purpose was more for Greinke to get his work in with a batter standing in the box.

Greinke said he wasn¡¯t sure when he was pitching again next, but he said it would likely be in a Cactus League game and that after that outing, he will likely throw every fifth day during the spring.

Scratch that

Matt Koch had been slated to start Saturday¡¯s Cactus League opener against the Rockies (1:10 p.m. MST), but his first game action will be pushed back.

Nick Green, a Rule 5 pick out of the Yankees organization, will get the start instead.

¡°Matt was slow to recover from his live [batting-practice] session and just has some general arm fatigue,¡± D-backs manager Torey Lovullo said. ¡°At this point right now, it just made no sense to me, [pitching coach] Mike Butcher and the medical team to force things.¡±

Koch and Green are both part of a large competition for the final two spots in the bullpen.

Speaking of the opener

One of the big storylines of the spring is Ketel Marte¡¯s transition from second base/shortstop to the outfield.

Lovullo said he believes it¡¯s best for Marte to get settled in the infield this spring before he appears in the outfield during a game.

With that in mind, Marte will start at second base against the Rockies on Saturday and will likely start playing center about a week or so into games.

¡°I just felt like to give him every opportunity to get back into the swing of it and feel comfortable, that was going to be the best spot,¡± Lovullo said. ¡°At some point, you¡¯re going to see him rotate to the outfield."