(Paul Sancya/AP)

Johnson had told Danny Espinosa and Anthony Rendon, among a few others, that he had once made all-star teams and won Gold Gloves at second base in the majors. But “he didn’t have to,” Espinosa said. “I knew. If you know baseball, you should know that.”

Johnson instructed the infielders on how to turn double plays at second, focusing on how they could protect themselves from injury. He wanted Rendon to have the lesson because, with Ryan Zimmerman signed long-term at third base, Rendon will have to move around the infield.

Even though Espinosa played second base at, or least near, a Gold Glove level last season, Johnson felt he needed fine-tuning at the position. Espinosa had played shortstop his entire college career, and he only played seven games at second base before the Nationals called him up in September 2010.

“Espi’s still leaving himself a little vulnerable, which I don’t like,” Johnson said earlier this week. “Espi’s got a college degree in second right now, but he don’t have his doctorate yet and he ain’t got the masters over there yet. So we’re going to have a little classroom session.”

As Johnson watched, the infielders flipped balls to each other around the base to practice turning the double play, focusing on moving through the base and out of the way of the base runner. Johnson had learned the footwork from Bill Mazeroski and Bobby Richardson, and he wanted to pass it along to his young infielders.

“To me, that’s a beautiful pirouette,” Johnson said. “I’ve seen a lot of second basemen, big-league second basemen, totally butcher it. But when it’s done properly it’s just a beautiful thing, and you never get hurt.”

Said Espinosa: “He just taught us different ways to turn double plays as far as going across the base. His main thing is, he always wants you protected. He doesn’t want to leave your front knee exposed for injury. We just worked on how to step through the ball and clear yourself.”

Johnson told Espinosa he often relied on his arm too much while turning double players, standing at the base for an extra split-second and rifling the throw to first, which left his front knee exposed. Espinosa plays second with a rare physicality, a ball of fast-twitch muscle with a glove attached. With improved footwork, Espinosa feels like he could take a step forward this year.

“Definitely,” Espinosa said. “I thought I turned a good amount of double plays, but there were plays where I rushed and I bobbled and I wasn’t able to turn two. I definitely felt there were times I could turn a double play better, easier, more efficient without having to be so forceful.”

This morning, Espinosa actually took grounders at shortstop, preparation for tomorrow when he’ll start at short in Lakeland. The Nationals want Espinosa to receive playing time at shortstop in case Ian Desmond gets hurt.

“I feel fine” at shortstop, Espinosa said. “It’s a little tough to go back to short. Second base, you have a lot more time. Short, you have to come get the ball a lot more. But I’m not worried about it.”