After collecting 17 strikeouts without a walk in 11 relief innings at spring training, Braves rookie Dan Winkler struck out the side in his one inning of work on opening day against the Nationals.

That’s 20 strikeouts, no walks and a .182 opponents’ average through 12 innings of work since the beginning of February. And even if no one will else is likely to remember those Grapefruit League innings for long, Winkler knows the strides he made down in Florida and in his first regular-season appearance.

He barely resembles the pitcher who made his major league debut in September, allowing two hits, two runs and a walk in 1 2/3 innings during two end-of-season relief appearances after Winkler’s 14-month rehabilitation from Tommy John elbow surgery.

The elbow feels at least as good as it did before the injury and surgery, he said.

“Maybe a little better, stronger,” he said. “But the biggest thing for me is just being comfortable on the mound. I’m just so comfortable, I’m kind of where I was (before surgery). Mechanics are good, mentality is good. Cutter’s there. If the cutter and fastball are there, I think I can go out there and compete.”

As a December 2014 Rule 5 pick from the Rockies who only spent a month on the active roster last season, Winkler must remain on the Braves’ 25-man roster for the first two months of the season, or else be offered back to Colorado for $25,000.

The way he pitched in spring training, it was an easy decision to put Winkler, 26, on the opening-day roster, even if the Braves were likely to be a little cautious and avoid using him in back-to-back games at the beginning of the season.

Before blowing out his elbow in July 2014, Winkler had a stingy 1.41 ERA in 12 starts for the Rockies’ Double-A affiliate, with 71 strikeouts and 17 walks in 70 innings. In four minor league seasons, all as a starter, he had a 3.79 ERA with 447 strikeouts and 130 walks in 429 2/3 innings.

Good command of all his pitches and a funky delivery that provided deception were strengths. Now, 21 months after surgery, Winkler’s command is better than ever and his fastball is a consistent 92-93 mph, good enough when located well and complimented by an improved cutter.

He relies on mostly those two pitches in a relief role, but Winkler still has a four-pitch repertoire.

“I still have a slider and a changeup, which comes in handy, something a little different,” he said. “I’ve gotten a lot of swings and misses on both of those. When we went down to Sarasota (at spring training) against the Orioles, I got strikeouts on the slider and changeup, too. Those are always going to be there, but I feel more comfortable with the fastball and cutter, to righties and lefties.”

After being a starter all his life before last season, Winkler has taken to the relief role.

“I didn’t know if I would (like it), but yeah, I do,” said Winkler, who likes the energy he feels coming in from the bullpen, especially in front of a big crowd like the opening-day sellout. “There’s something to be said about hearing your name (being introduced), getting the call, that adrenaline rush.

“I like both, though. They’re two different roles. Starting is more like a chess match, and then relieving is kind of just going out there, keeping the ball down and seeing how good your stuff can be.”