"Each guy's a little different," Preller said. "But we feel good overall with their potential to help the club."
Diaz, the only player of the three who has recorded a full season at Class A, is furthest along. The former Brewers prospect posted a 2.25 ERA while allowing three hits and four walks over eight Cactus League innings.
Meanwhile, Torrens (.167 average, 26 percent strikeout rate) and Cordoba (.179 average, 23 percent strikeout rate) weren't quite as impressive this spring.
"I felt good about who I saw in Diaz in Spring Training," said Padres manager Andy Green. "I'm not going to be afraid about throwing him into the fire a little bit more. For Torrens and Cordoba, find them, in an ideal world, a little bit of a softer landing."
Both Green and Preller were quick to invoke Luis Perdomo, last season's Rule 5 success story and the Club's starter for its' home opener on Friday. After a dreadful spring, Perdomo hit a low point on Opening Day 2016 when he surrendered six runs in an inning against the Dodgers.
"He had the wide eyes," Green said. "That was very, very tough for him. But he settled in and became a huge contributor for us and is now a member of our rotation, where the guy just flat-out earned it.
"Those are real challenges early on. You want to put Cordoba in a position to succeed. The ideal situation is not double switching him into a one-run game in Dodger Stadium and saying, 'Hey, go play shortstop.'"
Jabari Blash serves as the counter argument to Perdomo. With minimal playing time last season as a Rule 5 pick, Blash struggled, and the Padres designated him for assignment in May.
Ultimately, they worked out a deal with Seattle to keep Blash, but it was a lesson in the pitfalls of carrying a Rule 5 hitter who isn't quite big league ready.
The Padres have two this season, making Green's job of managing his bench "challenging." Cordoba showed flashes of potential, ending the Cactus League on a 4-for-11 stretch. But suffice it to say both hitters will need to perform better than they did on during camp to remain Padres.
"We'll look at it on a week-to-week, month-to-month basis, depending on where the club is at and where they're at," Preller said. "We're not looking to [keep] guys who won't be able to contribute at all. Similar to Perdomo, who early in the season struggled a little bit but as the season went on got better and better, that's what we're looking for."