Snake bites

• Besides picking a fifth starter for the rotation, the D-backs still need to make another decision before Opening Day about who will be the backup catcher to Miguel Montero.

Competing for the job are veterans Wil Nieves and Rod Barajas, both of whom have performed well this spring. Nieves has thrown out three runners while batting .321 at the plate, and Barajas has thrown out one while hitting .290. Barajas has shown more power in camp, collecting five doubles and two homers, while Nieves only has one extra-base hit.

"It's along the same lines as the fifth starter; we'll talk with [GM Kevin Towers] about it," Gibson said. "I came in today and watched Ian Kennedy's last two starts as well as last night's game, just to watch our catchers. It's a very close situation. It'll be a tough decision."

• Still recovering from an elbow injury, D-backs shortstop Didi Gregorius threw across the diamond Friday for the first time and could potentially play defense in a Minor League game before Spring Training concludes.

"He could at the end," Gibson said. "He's right on schedule. We've been very cautious with him, but he's starting to throw more and he'll probably do that again [Monday]."

Even though he hasn't appeared in the field in a Cactus League game this year, Gregorius has taken 19 at-bats so far in games as a pinch-hitter or designated hitter, amassing nine hits, including two homers.

"I want him to get close to 50 at-bats by the time he's ready to go 'full go,'" said Gibson, who added the shortstop will continue to hit in Minor League games as well. "He's going fine, though. He's great."

• Jason Kubel and Cody Ross will take up to 12 at-bats against Minor Leaguers Saturday at Salt River Fields. Ross is still making his way back from a calf injury and won't run the bases if he gets on, while Kubel is trying to find a rhythm at the plate as camp draws to a close. So far this spring, Kubel has just six hits in 36 at-bats.

"He's just kind of searching right now," Gibson said of Kubel. "He'll go over there and see how that goes."

• Saturday was Martin Prado's third start this spring in left field, mostly because of Adam Eaton's elbow injury, which will cause him to miss 6-8 weeks. The D-backs want to give Prado time in the outfield just in case they need him there in the regular season.

Tyler Emerick is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.