Moreover, two more Nationals relievers are among nine pitchers right behind with 10 appearances.
Right-hander Jon Rauch and left-hander Micah Bowie each have appeared in 11 games. Then there are Ryan Wagner and Jesus Colome at 10.
Closer Chad Cordero, with eight games, would normally be up there, too, had the Nationals presented more save opportunities.
"The bullpen is our strength," manager Manny Acta said. "I think the first week we had also put us in that situation. I think once things settle down like they are, we'll be able to stay away from certain guys and give 'em enough rest."
One reliever afforded such a luxury is Colome, who pitched three shutout innings in the Nationals' 14-inning, 6-5 victory over the Marlins on Friday night. Colome won't pitch again until Tuesday at the earliest.
Acta even told him that he could take a two-day vacation in the Dominican if he wanted.
"I'd like to see my family," Colome said, "but I knew he was joking with me. I feel fine now, like I can pitch if they need me."
Said Acta, smiling, "He said that because he knows he doesn't have to pitch."
Of all the Nationals relievers, Rauch is the standard by which pitching durability is measured. He pitched in 85 games last season.
"He's one of those guys that likes to be out there at least every other day," Acta said.
Rauch said he experienced some arm trouble as a young pitcher and that's why he revels in being a workhorse now.
"I just like being out there," he said. "To be able to go out there on a regular basis makes me feel good."
He said his arm has adjusted to the regular work.
"It's still attached," he said with a chuckle. "Your body gets used to a certain routine. I know now what I'm able to do and what I'm not able to do."
Bowie, the only left-hander in the Nationals' bullpen, is a relative newcomer to this workaholic routine. He never pitched in more than 38 games in a season in the Minors, and appeared in 15 for the Washington last season.
"It's just something that's happened," Bowie said of pitching in so many games this early in the season. "I like to be available to help."
Bowie had Tommy John elbow ligament surgery in 2003, and has experienced no arm trouble since then.
"So far so good," he said. "It's amazing to see a guy like Jon, going out almost every day. I just want to be here to help as well."
Cordero's tribulations: It has been a rockier-than-usual start for Cordero. The closer has given up 12 hits and has a 5.40 ERA in 8 1/3 innings. He's managed one save, but has two blown saves in the last four games.
Acta is right in his recall that Cordero got off to a bumpy start last season, but it wasn't this severe. Cordero allowed three earned runs in his first four appearances a year ago, but finished the month with a 2.70 ERA.
Acta has a suspicion of what's been troubling Cordero, who recorded 76 saves in 2005 and '06 entering this one, while Cordero has been checking out video of better days with pitching coach Randy St. Claire.
"The main thing he should worry about is location," Acta said. "If he throws strike one, I think things will change."
Acta recalled that when Cordero first joined the Expos, the forerunner to the Nationals, he would often start hitters with a fastball strike, then mix in his breaking pitches. Now, the manager said, he seems to be using a breaking pitch more frequently as an opener.
Acta hopes a save opportunity presents itself soon so Cordero won't have much time to ruminate over his recent struggles.
One thing the manager loves about Cordero is his unflappable demeanor.
"I don't know and the opposition doesn't know, either, whether he's struggling or not," he said. "That helps him big-time."
Talent is sometimes tough to evaluate: Nationals broadcaster Don Sutton was reminiscing recently about how challenging it can be to evaluate baseball talent. He considers himself Exhibit A.
As a youngster, Sutton pitched Tate High School of Pensacola, Fla., to a state small-school championship as a junior and lost in the state final as a senior, 2-1, to Palatka High on two unearned runs. Yet the scouting interest in him was minimal.
Sutton had his heart set on going to the University of Florida. So his high school coach, Pete McCleod, offered to make a call to then-coach Dave Fuller. According to Sutton, Fuller told McCleod that he didn't think Sutton was up to the rigors of pitching in the Southeastern Conference.
So Sutton had to enroll at Gulf Coast Community College in Panama City, Fla. After a distinguished year there and a subsequent gangbuster performance in a summer league, Sutton signed professionally, thus launching a Hall of Fame career in which he won 324 games.
Sutton laughs that when his high school coach called Fuller years later about another player, he reminded him that he had tried to convince him to sign Sutton.
"The guy that I recommended three years ago shut out the Cincinnati Reds last night," Sutton recalled him saying. "He would be a junior at Florida now."
Up next: The Nationals have an off-day Monday. They'll fly to Philadelphia after Sunday's game and open a three-game series with the Phillies on Tuesday. Right-hander Jason Bergmann (0-1, 3.94) will pitch the 7:05 p.m. ET opener.
Charles Nobles is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.