(Alex Brandon / AP)

The Nationals’ injury-plagued roster will receive a boost Tuesday when Jayson Werth, fresh off a destructive and productive five days at Class A Potomac, returns after he missed the last 28 games with a strained hamstring. The Nationals need desperately to get whole again, and Werth will give them one large piece.

“It’ll be nice to have him back,” shortstop Ian Desmond said. “He’s a huge part of our team, as far as leadership, character, things like that. And he can contribute on the baseball field. Like I said, it’s just a matter of time before we get our pieces back and start playing better and all these questions will be over with.”

In his five-game stint with Potomac, Werth went 9 for 16 with two walks, one double and two home runs. We already figured he could mash Class A pitching, but the gaudy numbers can only be a good sign. “That’ll be a shot in the arm,” Manager Davey Johnson said. “He must’ve been really feeling frisky. He’ll be ready to carry us on his shoulders, I’m sure.”

The Nationals will need Werth to live up to his stature – the most experienced, oldest and highest-paid player on the roster. With Bryce Harper on the disabled list, Wilson Ramos out for at least another few weeks, two ailing starting pitchers and an offense trending toward a historically bad on-base percentage, the Nationals in this moment need Werth to be more than complementary piece. They gave him that seven-year, $126 million contract so they could lean on him at a juncture like this.

Which Jayson Werth are they getting? Last year when Werth came off the disabled list in August, he transformed the Nationals from a decent offensive club into perhaps the best in the National League. He was at his grinding best, taking a boatload pitches, ripping line drives and keeping the line moving. In 54 games, he reached base at a .394 clip and scored 32 runs.

Before he pulled his hamstring this season, Werth had not provided quite the same production. His on-base percentage, oddly, dropped to .308 – a level it didn’t reach even when during his first season in Washington – and he walked only six times in 107 plate appearances. In a good sign for the recovery of his wrist, his power ticked up and he drilled four homers.

How important is a productive Werth to the Nationals? This may be statistical noise in a small sample, but maybe not. In the 27 games Werth played this year, the Nationals went 14-13. In those 14 wins, Werth had a .969 OPS. In the 13 losses, he had a .436 OPS.

Whatever version comes back Tuesday night, Werth will certainly help. With Harper out of the lineup, the Nationals’ corner outfield defense took a big hit. The advanced stats may not be crazy about Werth, but he will help that cause. He runs the bases well and provides a different kind of edge.

“It’ll be big,” first baseman Adam LaRoche said. “Just having him in there, you always hear about guys and their presence in the lineup. But he’s a guy that can wreak some havoc on the bases, great defender and has a knack for getting on base. That’s what we need right now.”

Werth mostly occupied the second spot in the order before he landed on the disabled list, and all non-Werth No. 2 for the Nationals this year have hit .193/.212/.248. Werth may not necessarily fit that black hole, though. Johnson could play around with his lineup and, without Harper, beef up the middle of the lineup. Werth’s on-base skills, though, seem best-suited for the top of the order, especially on a team having so much trouble reaching base.

The Nationals have fluid options in how they make room for Werth on the roster. They currently have eight relievers and four bench players. They could place Stephen Strasburg (lat strain) on the disabled list. They could send little-used Jeff Kobernus back to Class AAA Syracuse, but he provides more defensive versatility (though less potential for thump) than Tyler Moore, whose role figures to shrink with Werth back.

However the Nationals manage Werth’s return, what matters is how he plays. They don’t just need him healthy. They need a major lift.