SCOTTSDALE, Ariz. -- The D-backs open their Cactus League schedule Saturday afternoon (1:10 p.m. MST) against the Rockies at Salt River Fields under what will hopefully be sunny skies.

The game results don’t count, and every player’s stats will revert to zero come Opening Day, but that doesn’t mean there aren’t things to keep an eye on over the next five weeks.

Here’s what you should watch with the D-backs:

Closer competition

Greg Holland and Archie Bradley are the main competitors here, with Yoshihisa Hirano and Yoan Lopez others to keep track of.

Simulating save situations is impossible during Spring Training because, for one thing, by the time the ninth inning rolls around, the opposing team’s best hitters are long gone from the game. As a result, managers will use their closers earlier in the game a lot of times in an effort to give them a look at the other team’s starting lineup.

D-backs manager Torey Lovullo will not so much rely on numbers to make his decision on a closer, but he will rather look to see who is throwing the ball the best, so pay attention to what is being said about each guy’s stuff as the games pile up.

Can Marte handle center?

The D-backs' moves for position players this offseason revolved around the belief that Ketel Marte would make the transition from second base/shortstop to center field.

Outfield coach Dave McKay has liked what he’s seen from Marte in drills, but nothing simulates game action.

Keep an eye on how Marte tracks balls in center. Does he get good reads on balls off the bat? If for some reason Marte can’t handle center, it really throws a wrench into the D-backs' plans.

Lamb at first

Speaking of position changes, another big one to watch is Jake Lamb's shift from third base to first.

There’s little doubt that Lamb can handle first when it comes to fielding grounders or scooping balls in the dirt. His real challenge comes on things like bunt plays and getting far off the base when no one is on and a right-handed pull hitter is up.

If by the end of Spring Training Lamb seems comfortable with the fundamentals of the position, there should not be any concern with him there heading into the season.

Who catches Greinke?

Zack Greinke has always preferred to work with one catcher, and for the past two seasons, that has been veteran Jeff Mathis, who developed a great relationship with him.

Mathis, though, is now with the Rangers, so it will be interesting to watch who eventually gets paired up with Greinke this spring. The D-backs have four catchers -- Alex Avila, Carson Kelly, John Ryan Murphy and Caleb Joseph -- for what will likely be three spots on the roster.

Whichever catcher ends up catching Greinke will assure himself of not just a roster spot, but playing time at least once a week.