At some point the D-backs will want him to get regular at-bats, but at least for right now they are content that Tomas is learning enough just by being in the big leagues.
"He's on a certain program that we think is going to help him in his progression to being an everyday player," D-backs manager Chip Hale said. "People are having a hard time believing it because he's not getting at-bats every day, which is hard. But he's doing [work] offensively with our hitting coaches and then the strength coach; they're really working hard to get him to where we think he needs to be to be an everyday player."
Tomas has been getting extra work in the cage with hitting coach Turner Ward, and Dave McKay has worked with him on his outfield play.
In addition, the athletic training staff has him on a workout program they hope will help him with his agility.
The transition from Cuba to professional baseball has not been an easy one. First there's learning a new culture and a language barrier. On top of that, the way they prepare for games in Cuba is much different.
In the U.S., players arrive early in the clubhouse -- some have argued too early -- and wind up spending a lot of time watching movies, playing videogames or reading.
"In Cuba, they go to the field like one hour before batting practice," said Tomas' translator, Ariel Prieto, who pitched in Cuba before spending six years in the Majors. "They do everything one thing after the other. They get there, they get dressed, stretch, batting practice and then right into the game."
Prieto helped ease the transition for Yoenis Cespedes when he joined the A's in 2012, when Hale served as bench coach.
That gives Hale a little bit more of an understanding about what Tomas is dealing with, but he cautions that the two are different people and Cespedes was 26 when he came over, while Tomas is 24.
The increased time spent at the field and the longer season took its toll on Cespedes in his first year with the A's. So if Tomas plays less right now, maybe it will be a good thing.
"That was one thing with Yoenis in Oakland: After about 100 games in his first year, it was really tough on him," Hale said. "This way, I guess we're going to get the back 100 games with Yasmany. He's learning the routine and he's learning to be a big league player. He'll have a little easier time than Yoenis did because he was thrown right into the lineup."