Craig Stammen (Al Behrman / AP)

The struggles of the Nationals’ bullpen reached a calamitous low this week, not all a result of their own doing. Ross Detwiler couldn’t make his start Monday because of a slight oblique strain and left-handed long reliever Zach Duke took his place with Craig Stammen serving as his backup. Ryan Mattheus coughed up five runs on Sunday, punched a locker, broke his hand and landed on the disabled list. So after Monday’s game, the Nationals’ seven-man bullpen was down to four. During the 10-game West Coast road trip, the bullpen was handed a lead five times and squandered it three times.

Manager Davey Johnson has admitted several times this season, including this week, that it has been hard to manage the bullpen. Just as relievers were beginning to adjust to their determined roles, the starting pitchers had a string of long outings and deprived the bullpen of work and created rust. And it didn’t help that before the reinforcements of Yunesky Maya and Fernando Abad arrived, Johnson was basically operating with a six-man bullpen, as he still hasn’t built up enough trust in Henry Rodriguez yet to use him in precarious situations.

The Nationals bullpen has a 4.21 ERA, 22nd in the majors. They have, however, done that in relatively fewer chances. The Nationals bullpen has logged only 126 innings, the 24th highest total in the majors. Early last season, Johnson leaned more on his bullpen than his starting pitchers. Because of need, performance and injury this season, the reverse has been the case. This year, the starters have a 3.24 ERA, third best in the majors, over 289 1/3 innings, the fifth highest total. So in fewer innings, the bullpen has been worse.

Relative to the innings they’ve pitched, Nationals relievers have allowed too many baserunners. The bullpen has posted a 1.38 WHIP (walks and hits per inning pitched), 23rd in the majors, sandwiched between the poor bullpens of the Marlins and Cubs. The hits and walks, as evidenced by Drew Storen’s eighth in Wednesday’s game, have come at costly moments. The Nationals have blown eight saves (three each by Rafael Soriano and Storen), tied for fifth most in the majors.

Roles are jumbled. Soriano is the closer, Storen is the eighth inning set-up man and Tyler Clippard is the seventh inning reliever, who is also often brought in to face a left-handed heavy inning. Stammen has been perhaps the most versatile and valuable reliever, but hamstrung by his long reliever role. But with so many other factors swirling — performance, injuries, strong starting pitching, limited relievers — the bullpen configuration has been out of whack.

The relief that arrived this week may help alleviate the load. Depending on Detwiler’s progress, right-handed Yunesky Maya, a starter in Class AAA Syracuse, may not be needed. Left-handed reliever Fernando Abad, who Nationals evaluators have been high on after a strong showing in the spring, could help correct some of the imbalance of having only one left-hander in the bullpen. With Mattheus out for at least a month, Abad could give Johnson more options. And more than anything, the Nationals need a talented bullpen to perform more consistently in its opportunities.