Stephen Strasburg needed only 15 pitches to get six outs. (Alex Brandon/Associated Press)

Stephen Strasburg made his first start of the spring Tuesday against the Atlanta Braves in Lake Buena Vista and needed only 15 pitches to notch six outs. He said afterward that his mechanics weren’t perfect, but his stuff was effective against a lineup that Braves starterss Jason Heyward, Justin Upton, B.J. Upton, Freddie Freeman and Evan Gattis. Strasburg’s fastball sat between 94 and 96 mph.

“I feel good,” he said. “I know once I get my mechanics a little cleaned up and a little in sync I start to throw a little bit harder. Felt pretty good today. Felt a little bit out of sync at the same time, but that’s kind of how it happens every year. Felt good and excited to get back out there.”

Strasburg allowed one baserunner — a single from Justin Upton in the second inning, which he erased with a double play — so he didn’t have much of an opportunity to work on holding runners, a point of emphasis for him this spring. He was pleased with the progress on his slider, a pitch he added this spring with the hopes of using it against left-handed batters. He threw at least three.

Strasburg threw two sliders to B.J. Upton; one was called a strike and the other got him a strikeout on a 3-2 pitch. Strasburg is using this spring to gauge hitters’s reactions to his new pitch.

“They’ve never seen it before, so I want it to look as much like a fastball as possible,” he said. “If I get a little bit of movement, that’s all that I’m looking for. Like I said, I’m not gonna dump my other offspeed pitches for it, it’s just gonna be something to keep them from cheating to the fastball as much.”

Added Manager Matt Williams: “It was good. It’s just another wrinkle. Another pitch off of his fastball that’s got really good velocity. And we saw that he can get a lot of swing throughs with that and can neutralize left-handed hitters. It was good.”

(James Wagner/WP) (James Wagner/WP)

>>> Williams has put the team through situational defense drills throughout camp and is using spring training games as a chance to test out certain situations. So after Luis Ayala loaded the bases in the eighth inning and had only one out, Williams called for a five-man defense and played them in, hoping for a double play. First baseman Brock Peterson moved toward second base and right fielder Steven Souza Jr. stood near first base. The two even switched gloves. (See the photo.)

Braves infielder Philip Gosselin smoked a bases-clearing triple to right field, where Souza would have been playing, so the plan backfired. Ayala’s pitch was over the plate, but Williams was hoping a lower sinker could have induced a double play out of an inexperienced right-handed hitter. Even though the Nationals lost, 8-4, that moment provided a light-hearted example of Williams’s meticulous preparation.

“It’s one of our plays,” he said. “We’ve got to work on it just in case we need it at some point. Figured, OK, we’ll try it. We’ll see what it looks like. It was fun.”

>>> Drew Storen made his first appearance of spring. He came on in the seventh inning and walked the first two batters he faced. Pitching coach Steve McCatty came out to settle him down. After getting Dan Uggla to fly out to left field, Storen allowed a two-run double to Andrelton Simmons before getting out of the inning with two groundouts.

Storen and Williams did not seem overly concerned with the results.

“You just tend to speed up,” Storen said. “You get in a game and face hitters and maybe try to throw a little hard. But I made the adjustment. That’s the big thing. I’d probably be a little more frustrated if I didn’t come back and find the zone. Made the adjustment, got on top of the ball and made a couple good pitches. So that’s really what it comes down to at this point.”

>>> Outfield prospect Brian Goodwin, starting and playing center field, made a nifty diving catch in the first inning to rob Freddie Freeman of a would-be double. He went 1 for 3 — the double hit the wall in center — and scored a run. Second baseman Anthony Rendon also made a slick defensive play, ranging far to his left to snare a groundball in the third inning and jumping to his feet in time to throw out Heyward.

>>> Ian Desmond is 3 for 3 in stolen base attempts this spring, and the Nationals as a team have swiped eight bases in four games. In the seventh inning, Williams was aggressive again with a planned play. With two outs and runners on the corners, Jamey Carroll broke for second base and then Goodwin took off for home.

With Carroll nearly getting caught in a rundown, Goodwin had an opening to get home and forced second baseman Dan Uggla to make a hurried and wild throw home. Carroll was safe at second and Goodwin scored.

“We’re trying to look at everything we possibly can,” Williams said. “So if the situation presents itself, we might as well try it so we understand us and what we can and can’t do. It was good. Goody could have got a little bit earlier break on it but the pitch before he was going so we decided, ok, let’s try it again and see if that’ll work. That one worked. Eventually. It wasn’t the perfect timing but we’ve got to work on that stuff.”

>>> Pitching prospect A.J. Cole had a clean second appearance than his first. He notched six quick outs without allowing a hit. He faced some of the Braves starters and struck out B.J. Upton and Evan Gattis.

>>> Taylor Jordan and Ayala didn’t look as sharp in their second outings of the spring. Jordan allowed two runs on five hits, leaving pitches up the strike zone. After three hits and an error by Bryce Harper in the fourth inning, Jordan escaped with two strike outs and the help of Wilson Ramos, who threw out Justin Upton trying to steal second base.

>>> Harper’s plate discipline has looked good in two games so far: he has drawn three walks in six plate appearances.