Tommy La Stella may be a rookie, but the Braves second baseman has performed more like a seasoned pro.

La Stella has served as the Braves’ second baseman in all but two games since his May 28 debut. In that time, he’s proved to be clutch on defense and offense.

On June 27, Dan Uggla played his final game as a Braves second baseman, though he wasn’t released from the team until July 18. But La Stella said he doesn’t feel more confident or comfortable in his position on the team now that Uggla is gone — mostly because he’s been confident and comfortable from the start.

“I wouldn’t say I’m more comfortable than I was before,” La Stella said. “I’ve felt good the whole time I’ve been up here, so I don’t really think anything has changed. All that decision-making stuff is so far out of our control, you can’t concern yourself with that process and everything like that once you’re in here.”

That understanding of his role on the team is what fellow rookie Shae Simmons believes has made La Stella so successful.

“He understands the scenarios and situations and how life works. The more productive you are here, the more consistent you are, the longer you’ll stay, “ Simmons said. “There’s a lot that goes into it, but he just understands the game, and he doesn’t try to do too much.”

Simmons and La Stella made their major league debuts three days apart. Simmons made his May 31, so it only makes sense for the rookies to be friends. But La Stella and Simmons aren’t just friends or just locker mates, they’re also roommates.

The pair first became road roommates while on the Braves’ Double-A Mississippi team about a year ago. After that they also lived together during Arizona Fall League, so deciding to live together in Atlanta was a natural progression.

“So unfortunately I spend the most time with him, probably,” La Stella said jokingly.

La Stella, 25, and Simmons, 23, recently moved into an apartment together in Atlanta. But both agreed they’re rarely there, and when they are, it’s only to sleep and eat before either heading to Turner Field or the airport.

“We got comfortable just talking about the game with each other and just hanging out,” Simmons said. “We just stay out of each other’s way and just let each other live, so it’s not bad.”

Overhearing Simmons say “we stay out of each other’s way” from the locker next door, La Stella couldn’t help but chime in: “That sounds great,” he said, sarcastically.

The two may banter like brothers, but at the end of the day, they’re both contributing significantly to the team.

Simmons, a right-handed relief pitcher, has pitched 21 innings since his late May debut. In that time, he recorded one save, eight holds, one win and two losses — both of which came in back-to-back appearances July 19 and July 21.

“I think it’s also a young kid coming out of the bullpen in certain situations, and he’s got to get used to it,” Braves manager Fredi Gonzalez said of Simmons’ recent losses. “From what I know of him since he’s been here, he’ll be fine.”

Simmons may be struggling with certain situations, but his roommate isn’t.

“He’s been real impressive. It’s hard to come up in those situations, especially as a rookie, and come through for your team like that, and he’s done it a lot,” Simmons said of La Stella’s productivity. “He’s pretty consistent with it, but it’s not going to be that way every time, but so far he’s done what he needed to do.”

Since being called up, La Stella has 13 runs, 51 hits and 23 RBIs in 181 plate appearances, as of Friday afternoon.

He’s fluctuated between the seventh and second positions in the batting order, though he’s made most of his appearances batting seventh. La Stella batted second in all four of Atlanta’s recent games against Miami. This likely is because of La Stella’s almost perfect productivity in bases-loaded situations. As of Tuesday, the rookie was 6-for-7 with the bases loaded.

“I don’t really know what to attribute it to, to be honest with you. It’s always nice to come through in a bases-loaded situation where runs are on the line,” La Stella said of the trend.