The Nationals will try to start putting their season back together tonight, as they open a homestand against the New York Mets. They woke up to some good news – no Matt Harvey this series – and some bad: They are down a season-high seven games in the National League East following the Braves’ victory last night over the Pirates.

Undeniably, the main reasons the Nationals have reached this point are injuries and impotent offense. But beneath those neon-light failings has been underlying erosion at the edges of the Nationals’ roster. Almost every small decision Mike Rizzo the Nationals’ front office made this offseason has to this point not worked out as they hoped, and the roster has often been managed in a suboptimal fashion.

The Nationals’ backup position players and bullpen appeared to be strengths at the start of the spring. They brought back their excellent reserves from last season, and maybe they didn’t have a lefty set-up man, but they had a stockpile of power arms in relief. Now, two months in, the Nationals have the least productive bench in the majors – which has been a dagger as they’ve needed to replace a confluence of injured players – and their 4.00 bullpen ERA ranks 18th in the majors.

In the spring, it was taken for granted the Nationals’ bench would be just as strong as last year. The same cast had come back, and if anything it seemed like young players Steve Lombardozzi, Tyler Moore and Roger Bernadina would improve.

Two months into the season, it looks more like a classic warning sign was not been heeded. Four players all had breakout seasons. This year, all of them have regressed toward the norm. Combined, per FanGraphs.com, Chad Tracy, Moore, Bernadina and Lombardozzi have accounted for -2.7 wins above replacement.

Considering the latter three have become semi-everyday players because of injury, this has not been a small problem. In hindsight, the Nationals’ decision to let Michael Morse go may have been crucial. Because of injuries, there would have been enough at-bats for Morse. It would have been a risk paying Morse $6.75 million to be a bench player, but then there is little risk anticipating injuries over the course of baseball’s marathon season.

The bullpen, too, has been more of a headache than could have been predicted. Closer Rafael Soriano has been the least of their worries, and Manager Davey Johnson has in general not been concerned with his relief corps. This weekend, he answered a question about the bullpen’s difficulty with left-handed hitters by saying the Nationals were not scoring enough runs.

Still, it has been an issue. This winter, the Nationals bet this winter they could lose left-handed relievers – Tom Gorzelanny, Sean Burnett and Michael Gonzalez –without allowing it to diminish their effectiveness against left-handed hitters late in games. Through one third of the season, it has become clear, the plan has mostly backfired. Nationals relievers have allowed opposing hitters a .289 batting average this season.

Part of the plan worked out – Tyler Clippard has allowed only six hits in 42 at-bats against lefties, although that includes four hits in the last five at-bats. Drew Storen (.348 average against lefties), Ryan Mattheus (.452), Craig Stammen (.302) and the one lefty in the opening day bullpen, Zach Duke (.448) have all been mauled by lefties.

Fernando Abad’s addition should help, and there have been some signs of improvement against lefties, particularly from Storen.

“I know early in the season, I struggled with it,” Storen said. “The same thing happened last year when I first came back – I struggled with them. But then you make the adjustment, and everything is good. It’s just getting that good sinker. I wasn’t commanding the sinker as well as I wanted, and I wasn’t getting the depth on it.”

Several players on the edge of the Nationals roster have underperformed, but the management of those players has fallen short. The Nationals have constantly played with a 23- or 24-man roster as hurt players stayed off the disabled list. There have been few glaring instances when playing a man short cost them a victory, and throughout the season every team will rest injured players for a few days. The Nationals, though, have they have frequently not achieved the fundamental roster management aim of giving the manager 25 players with which to work.

It took the Nationals 11 days to place Ross Detwiler on the disabled list. Bryce Harper missed five consecutive days before he landed on the DL, and that was after he toggled in and out of the lineup for a month. Danny Espinosa missed four days with a fractured wrist, which team doctors told him he could play through six weeks earlier. Again, that’s going to happen over the course of the year, but it has occurred more than necessary.

As the Nationals have struggled to a 28-29 record, they have made no changes aside from injury-related roster moves. Other teams demote underperforming players all the time. The Nationals have rearranged their roster plenty because of injury, but they have not designated or optioned any struggling players. After April, they could be lauded for resisting temptation to overreact. After May, two months into the season, it’s appropriate to evaluate the need for roster alterations.

Letting Corey Brown (.959 OPS at Syracuse) play a corner spot with Bryce Harper out, if only for defensive purposes, would be a possible upgrade. In the bullpen, Henry Rodriguez’s performance Saturday night should make the Nationals consider his efficacy on the roster. Three years into his Washington tenure, he still cannot be counted on to perform simple tasks – throwing strikes, holding runners – in crucial situations. He is walking 8.0 batters per nine innings. In close games, the Nationals are playing with either a six-man bullpen or a liability.

There are two big reasons why the Nationals have underachieved, a dismal offense and a rash of injuries. But there are plenty of smaller problems deeper on the roster, too. Add all of them up, and that is how a World Series favorite finds itself trying to fight out of being under .500 in June.

FROM THE POST

The Nationals need to place Stephen Strasburg on the disabled list and mix in common sense with their toughness, Boz writes.

Bryce Harper shouldn’t be making his own decisions on when to play, Tracee Hamilton writes.

Boz chatted.

FROM YESTERDAY’S JOURNAL

Romero opts out

Werth coming back

Solis on the mound

Second-round gems

LaRoche on Espinosa

NATS MINOR LEAGUES

Syracuse 6, Pawtucket 5: Anthony Rendon went 0 for 5 with two strikeouts. He played second base for the third straight game since his promotion to Syracuse. Corey Brown went 4 for 5 with two home runs and a double. Mike Costanzo went 3 for 5 with two homers. Danny Rosenbaum allowed two earned runs in six innings on eight hits and two walks, striking out five.

Harrisburg 6, Trenton 2: On a rehab appearance, Christian Garcia allowed no runs in one inning on one hit and no walks, striking out none. Garcia has made two appearances for Harrisburg. Taylor Jordan allowed one earned run in seven innings on three hits and one walk, striking out four. Steven Souza went 2 for 4 with a home run. Sandy Leon went 2 for 3 with a double and a walk.

Potomac 2, Myrtle Beach 1: Taylor Hill allowed one run in 8 2/3 innings on three hits and two walks, striking out seven. Jason Martinson and Adrian Nieto each went 1 for 4 with a solo home run.

Lexington 5, Hagerstown 2: Tony Renda went 2 for 5. Ivan Pineyro allowed two runs in 5 2/3 innings on five hits and one walk, striking out 10.