Catchers Jhonatan Solano, Sandy Leon and Jose Lobaton (left to right). (John McDonnell/The Washington Post)

On Thursday morning, the last day of workouts before the Nationals begin their Grapefruit League games, Sandy Leon, Jose Lobaton, Wilson Ramos and Jhonatan Solano stood around home plate at Space Coast Stadium and listened. Bench coach Randy Knorr, a former major league catcher, instructed the catchers how to set up on the first base side of the plate, instead of standing over it, receive a throw and then turn to reach over the plate to make a tag. Defensive coordinator/advance scout Mark Weidemaier and third base coach Bobby Henley stood nearby and offered advice.

Beginning Friday, the Nationals, like the rest of MLB, will begin play under baseball’s new rules aimed at preventing the most egregious of home plate collisions. In essence, the Nationals coaches were teaching the Latin American-born catchers, who had still been fuzzy about the new rules, that they couldn’t block the plate unless they had possession of the ball, as the new regulations state. The catchers, however, are changing the way they have played their entire careers.

“We are a little bit [confused] because that new rule, for a catcher, we have to block the plate,” Ramos said. “We don’t want that guy to score easy. But right now, the new rule help the catcher a lot. We need to be out of the runner’s line. That’s the new rule and we will have to do that.”

Early in the morning, Knorr, who coaches the catchers, and a Nationals video coordinator showed the players visual examples of what they need to do now under the new rules. Ramos said that he still needs to see more video and, more than anything, try out the slight changes in spring games. (There exceptions, according to the rules: for example, if the catcher has no other way to catch the ball but to block the runner’s pathway and contact in unavoidable, the umpire won’t consider it a violation.)

“During the spring we have to learn that,” Ramos said. “If it happens, it happens. I want to work on that, stay out of the runner’s line, but during the games you don’t have time to think in that situation because sometimes you don’t have time to react. So sometimes with the ball, you don’t know where the ball is coming from. If the throw’s in the runner’s line, you have to catch it. But we have to be ready to get hit all the time.”

A day earlier, Leon was still unsure what the new rules meant. After Thursday’s session, he had a better grasp of the regulations and their impact. The clearest explanation, Leon said, is that he has to let runner get home — unless he has the ball. Runners who violate the rules  are out and teammates must return to the last base at the time of the collision.

“They can’t hit the catcher in any way,” Leon said. “But if you’re block the plate, they can. They can’t use the elbow or the shoulder. They can only hit you. I think it’ll be harder for the runners because they won’t know to get home, slide, etc.”

Leon suffered a bad ankle sprain on May 14, 2012, his major league debut, in a collision at home plate with Chase Headley. Leon said the throw home pulled him into the runner’s path to field it. “I wouldn’t have tried to get the ball and it would have prevented if the rule was in place,” he said. “But it wasn’t and it happened. What happened happened.”

>>> Ryan Mattheus, who has been dealing with tendon irritation in his chest, said he is feeling better. He can take deep breaths again and ran on the treadmill. He is slated to be evaluated by a doctor on Friday and, if cleared, could be allowed to resume throwing soon after.

>>> Denard Span turned 30 on Thursday and as he stepped into the batter’s box during batting practice the dozen or so fans in attendance watching workouts serenaded him with “Happy Birthday.” One fan, however, yelled “Old man!” to Span after the song ended. Span, in his usual good humor, laughed it off and later tweeted about it.