The Washington Post’s Dan Steinberg, LaVar Arrington, Mike Wise and Jonathan Forsythe discuss debate the Nationals’ growing rivalry with the Phillies. (Post Sports Live)

Craig Stammen wants the baseball. He wants it today. And tomorrow. And if Washington Nationals Manager Davey Johnson will allow him, the day after that, too.

In his first full season as a reliever last year, Stammen was a workhorse. He excelled at the undervalued and unglamorous role of middle-inning reliever. He logged more innings than all relief pitchers in baseball save for one, and missed that distinction by one out. He made more multi-inning appearances than any other reliever.

If needed, he would have thrown more.

“Bulldog,” catcher Kurt Suzuki said of the right-hander. “He’s coming at you, coming to get you.”

Added Nationals pitching coach Steve McCatty: “He’s a big ol’ stud from Ohio.”

Stammen, 29, a former high school quarterback and shortstop from tiny North Star, Ohio, essentially is the Nationals’ fixer in the middle of the game.

Need two innings to bridge the starter to the late-inning relievers? Need to give tired relievers a day off? Need three innings because a starter struggled? The 6-foot-4, 225-pound bull, as Johnson refers to him, will do it.

“I’m proud of that nickname,” said Stammen, who as a youngster helped his father with his farm equipment company. “That’s kinda how I grew up. Blue collar, kinda do whatever the manager says and do it as best you can. Have everybody jump on your back and ride you.”

On many occasions, Stammen did just that. Last season, he appeared in 59 games and logged 881 / 3 innings, compiling a stellar 2.34 ERA. He struck out 8.9 batters per nine innings — the second-highest rate among returning Nationals relievers behind Tyler Clippard. He induced groundballs from 45 percent of the batters he faced. After seven seasons developing as a starter, Stammen found a fit for his endurance, power arm, wipeout slider and dominant sinker.

“The way I feel my body works, I prepare myself for the maximum and the stuff less than that will be easy to overcome,” he said. “So that’s kinda how I prepare myself. It actually fits in well in the role that I’m in.”

Stammen reached the major leagues as a starter in 2009 but struggled because of arm soreness. He underwent surgery that September to remove bone chips in his right elbow.

Still a starter at Class AAA Syracuse, he was called up to the majors as a reliever in 2011.

Last spring, Stammen knew he had to make the team as a reliever because he wasn’t going to crack the starting rotation. If given the chance to start again, he feels he would do better than before, but he understands his role in the bullpen and relishes it.

“When you go to the bullpen, you do strike out more people because you’re not really setting guys up for later in the game, you’re just throwing whatever you got,” Stammen said. “Bam, bam, bam, get ’em out. I have gotten better as a pitcher as my career has gone on, and I think that’s part of it.”

Stammen excelled last season because of the development of his dominant sinker. McCatty, Stammen’s former pitching coach in Class AAA Syracuse, and Nationals minor league pitching coordinator Spin Williams urged Stammen to throw the pitch more.

Stammen learned new grips for the sinker from Livan Hernandez, famous for his array of slop during his tenure with the Nationals from 2009 to 2011. Stammen said he felt more comfortable with his sinker last season, particularly his ability to command it on both sides of the plate.

Stammen said he thinks his sinker is more effective and moves better when he throws more often and his arm is a little tired; the fatigue prevents him from overthrowing the pitch. In the final appearance of last regular season, his third straight appearance without rest, Stammen faced six Philadelphia batters over two innings and struck out all six. The seven times Stammen appeared in a game with zero days of rest last season he gave up no runs.

Stammen has also excelled in one of the most overlooked innings in baseball. According to 18 seasons of data complied by Sports Illustrated, the first and sixth innings are the highest-scoring innings of the game — when starters face an opponent’s best hitters and when they often leave the game, respectively. Stammen threw in the sixth inning in 21 of his 59 appearances last season and had a 1.83 ERA.

Stammen prepares himself in the offseason — running, lifting and watching what he eats — with a large workload in mind. He wants to be ready, just in case the Nationals were to need an emergency start.

While the Nationals monitor the innings of other relievers, they aren’t worried about wearing down Stammen. His struggles in the playoffs were attributed to mechanical flaws, not fatigue. In fact, if Johnson were to ask Stammen to carry an even heavier load this season, Stammen’s starter mentality would take over.

“At the end of the year, I felt strong and didn’t feel like I wore out at all,” Stammen said. “If he wants me to pitch more, that’s fine with me.”