PEORIA, Ariz. -- Padres right-hander Jacob Nix has been shelved with soreness in his right arm, throwing an unfortunate wrench into the team's rotation battle.

Nix threw one inning Tuesday against Oakland before the game was canceled due to rain, and he pitched three more simulated frames in a nearby batting cage, totaling about 64 pitches. He felt some minor soreness the following day. On Thursday when Nix began to play catch, it flared up, and he was shut down.

Nix, the team's No. 19 prospect, underwent tests on Friday, which revealed no obvious structural damage in his elbow. It's unclear whether more tests will be required, and the extent of his injury remains unclear. The team is hopeful he can resume throwing next week, but also said that it’s too early to make that declaration.

"It's one of these things that we’re hoping [lasts] a day or two," said Padres manager Andy Green. "You never really know until they pick the ball back up and try to throw again. Our anticipation is he'll pick the ball back up in a couple days, see how feels, and if he doesn't feel well, we'll probably shut him down for a considerable period of time at that point. If he feels good, he'll get right back on the horse."

Nix is among 10 candidates for the Padres' rotation, and he was perhaps the favorite for the No. 5 starter role. His injury might make Opening Week something of a lofty target. Green acknowledged that Nix would sit at the back end of the rotation if he were to recover quickly and make the roster.

The injury could present an opportunity to a handful of other pitchers in the mix for that No. 5 spot. Robbie Erlin, Bryan Mitchell and fellow top prospects Logan Allen and Cal Quantrill are candidates. Allen and Quantrill started the team’s split-squad games Saturday.

In nine starts for the Padres last season, Nix posted a 7.02 ERA with just 4.5 strikeouts per nine innings. But he was confident that improvements with his breaking ball might catapult him to success in year two. Plus, he felt that offseason surgery to address a sports hernia might make him freer in his delivery.

In four spring outings, including the rain-shortened one, Nix has a 5.87 ERA with five strikeouts in 7 2/3 frames.

Tatis breaks out

A week ago, Padres' top prospect Fernando Tatis Jr. missed three games after having three wisdom teeth pulled. Upon his return, he went hitless over his next seven at-bats.

Not to worry. Tatis, sans wisdom teeth, can still rake.

The 20-year-old shortstop went 3-for-4 in Peoria on Saturday afternoon with a pair of doubles. In doing so, he brought his spring average to .303 with a .997 OPS.

Covering the bases

First: Franchy Cordero reminded the Padres why he's expected to be such a valuable piece of their lineup against right-handed pitching. He launched a mammoth two-run homer over the right-field bullpen, giving the Padres a 5-3 lead in the second. Cordero is the only left-handed hitter in a crowded Padres outfield, and he's capable of playing all three positions.

Second: Ian Kinsler returned after missing three games with a jammed finger on his right hand. He went 1-for-3.

Third: Mitchell pitched 1 2/3 hitless innings in a relief role. After some early-spring struggles as a starter, it's unclear where Mitchell stands in his battle for a roster spot and whether he's still a candidate for the rotation.

Home: Catchers Austin Hedges, Francisco Mejia and Chris Stewart have impressed this spring. Andy Green on the possibility of carrying three catchers on the Opening Day roster: "We didn't come into spring with that at the top of our agenda. But we like what our guys have done in camp, and we like the uniqueness of their skill sets. It's definitely not something we're trying to make happen. But if it turns out to be our best option in a couple weeks, we won't run from it."

Up next

Righty prospect Pedro Avila makes his first start of the spring Sunday afternoon when the Padres host the Angels at 1:10 p.m. PT. Avila has never pitched above Class A Advanced, but he's been sharp in the Cactus League with a 1.29 ERA in three outings. It's probably Avila's final chance to make an impression before heading to the Minors. Sometime next week, the Padres are expected to pare down their starting pitchers in big league camp.