Jace Peterson went to big-league camp with the Braves this spring and then tore it up in Grapefruit League to earn a roster spot to open the regular-season.

Now Peterson is a mainstay for the Braves at second base, with 20 starts there in the team’s first 26 games. It’s been a rapid rise for a prospect who wasn’t a sure bet to make the big-league roster after arriving from the Padres in the Justin Upton trade.

Peterson is the only one of the four prospects the Braves acquired in that trade to make the big-league roster out of camp.

“When I got to come to spring, I think that was good being in a big-league camp with the guys and kind of building chemistry,” Peterson said. “Now that the season is here it’s already been a month. The year goes by fast. I think we have a clubhouse that has fun, that comes to work every day and everybody works hard. I think that kind of makes it comfortable and has everybody on the same page.”

Peterson ended up in San Diego’s minor-league camp before the end of spring training last year and then saw mostly spot duty while playing 27 games for the Padres in 2014. By contrast, he hasn’t been left on the bench for more than a game at a time with the Braves.

Peterson’s production has been up-and-down, as expected for a 24-year old still trying to establish himself in the majors. It’s been on a general upswing lately, with a .321 average and .394 on-base percentage in his past nine games entering Monday.

That run lifted his season numbers to .239 batting with a .312 OBP.

“I try to come and compete and do something positive for the team every day,” Peterson said. “Whether it’s at the plate, or making a play in the field, or taking an extra bag, whatever it is. I really don’t look at the numbers too much. I know at the end of the year if I am playing, my numbers will be where they are supposed to be.”

Peterson’s potential prompted the Padres to draft him in the first round out of the 2011 draft out of McNeese State. Baseball American rates him as the Braves’ ninth-best prospect.