Clippard, a candidate to be in the starting rotation, had a rough first inning, giving up a leadoff home run to Alejandro De Aza and having a tough time throwing strikes. However, Clippard settled down the next inning without giving up a run.
"My command is not what I want it to be, but I felt good, which is the most important thing at this point in time," Clippard said. "I felt strong. I made some quality pitches. But obviously, there is some work to be done."
If there is a silver lining, it's that Clippard's mechanics are improving by the day. After Clippard became a big leaguer with the Yankees last year, the Nationals took notice that he changed his mechanics after his promotion. He then had problems finding his release point, but Nationals pitching coach Randy St. Claire has helped Clippard fix the problem.
"Right now, everything seems to be where it should," Clippard said. "In the past, it was tough to focus and know exactly what I was doing on my own. Randy let me know what I was doing wrong. I felt like I made the adjustment really quickly, and in my last few bullpens and live batting practice sessions, they were pretty good. The second inning Friday, it was a lot better."
Back in action: Second baseman Bret Boone played in his first game since 2005 and went 1-for-2 with a double against Marlins right-hander Burke Badenhop.
"There was anxiety going up to the plate again because it has been so long for me," Boone said. "It's important to show that I can do it like I used to do it. I felt great. I haven't run around the bases in so long. The first day, I didn't expect much."
Injury report: Infielder Rob Mackowiak aggravated his right abdomen while running the bases in the sixth inning against the Marlins. He is listed as day to day. Mackowiak, who believes he may have broken some scar tissue, had hernia surgery during the offseason.
This and that: First baseman Nick Johnson played in his second game of the spring and went 1-for 2 against the Marlins. ... Third baseman Ryan Zimmerman is 3-for-3 in his last two games.
Coming up: Washington returns to Space Coast Stadium in Viera, Fla., to play Baltimore on Saturday at 1:05 p.m. ET. Nationals right-hander John Patterson will oppose Orioles right-hander Daniel Cabrera.
Bill Ladson is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.