(Photo by Jonathan Newton / The Washington Post)

Nationals set-up reliever Tyler Clippard, perhaps the most durable reliever in the major leagues, didn’t fully participate fully or throw during the Nationals’ workout on Friday, a “precautionary” measure after he felt tightness in his back. Clippard plans to return to practice tomorrow and throw a bullpen session Monday.

“I wanted to be out there, but they’re not letting me,” Clippard said. “I just want be 100 percent, and they do, too. It’s early.  I mean, during the season, it would be nothing. They had to hold me down today. I wanted to get out there, and they wouldn’t let me.”

Clippard felt minor tightness in his back early in the week, pretty standard for this phase of spring training. He focused on his legs during a weightlifting session and felt a little more soreness.

“I told them, which I probably shouldn’t have,” Clippard said, laughing. “And then they were like, ‘All right, take it easy.’ ”

In other participation news, Bryce Harper went through a full batting practice Friday. On Thursday, Harper cut short his session after he had trouble getting loose, a product of a long team meeting disrupting his routine, Manager Matt Williams said. Williams reiterated today that Harper’s shortened practice Thursday had “absolutely nothing” to do with his surgically repaired left knee.