Ian Krol couldn’t have envisioned opening the season in Triple-A after being traded from the Detroit Tigers to the Braves in November. But the hard-throwing left-hander used the month in the minors to his advantage.

Since being called up by the Braves on May 10, Krol has provided a needed bullpen boost and allowed the Braves to lean a little less on rookie lefty Hunter Cervenka, a workhorse in his first month in the majors.

Krol, who made 110 relief appearances for the Tigers during the 2014-2015 seasons, posted a 2.57 ERA in eight appearances for the Braves before Wednesday, allowing nine hits, two runs and two walks with 11 strikeouts in seven innings.

Right-handed hitters knocked him around a bit early and had a .421 average (8-for-19) against Krol, but lefties were just 1-for-9 with no walks, one hit-by-pitch and four strikeouts before Wednesday.

“He went to work when he got to Triple-A,” said Braves interim manager Brian Snitker, who had Krol on his Triple-A Gwinnett team before the lefty was called to the big leagues (Snitker was promoted from Triple-A manager after Fredi Gonzalez was fired as Braves manager last week).

“When I had him down there I said, ‘Your stuff is really good.’ And he’s done nothing but a good job since I’ve been here,” Snitker said. “I think the more he’s out there and doing that, the more confidence he gets, he could be a very valuable piece for us.”

Krol, who turned 25 this month, got sent to minor league camp late in spring training and said he worked there on some subtle aspects of his approach and routine. His Gwinnett pitching coach was Marty Reed, now the Braves bullpen coach.

“There’s little things, like throwing off the mound if I didn’t get in the game for two or three days, doing that before the games, just to sharpen up,” Krol said of improvements he made before and since being called up. “First-pitch strikes, that’s a big thing to open up your arsenal. I’ve been doing that pretty well. Most of my pitches have been down (in the strike zone), and when they are up they’re in the right spots to be up.

“So I think, all in all, everything kind of came together. My arm kind of got in the swing of things, kind of got, I guess you would say, used to the baseball season. It usually takes two or three weeks for your arm to get in shape. Spring training helps but…. All in all, I think it’s just a confidence thing, when you’re going good you’re going good. Things have been working out really well.

“I know in the past I’ve struggled here and there, it’s been a long road. But right now it feels good.”

Reed was promoted from Gwinnett pitching coach to Atlanta pitching coach last week when Snitker took over as Braves manager. Reed replaced Eddie Perez, who moved from bullpen coach to first-base coach.

“Having Snit and Marty up here is awesome,” Krol said. “Marty helped a lot. Marty helped mechanically. We didn’t do too much, but as far as working before games off the mound and stuff, that was a big part of me getting back up here.”