SAN DIEGO -- For a change, it wasn't another extra-inning game Wednesday that nearly depleted the Padres' haggard bullpen, though the alternative certainly wasn't much better.

That bullpen, still recovering from a 17-inning game on Sunday, had to make up the final seven innings of San Diego's 7-3 victory over the Nationals at PETCO Park after starting pitcher Clay Hensley left after straining his right groin.

And now, on the cusp of starting a seven-game road trip on Friday in Florida, the Padres will not only likely add another reliever to their bullpen but will have to replace their No. 3 starter, as Hensley appears headed to the disabled list.

"It doesn't look good," Padres manager Bud Black said of Hensley's injury. "I don't know the significance of the strain. But from all indications, it looks like it's going to be a DL. ... Right away the doctor felt as though it would be two weeks."

No, this wasn't exactly what the Padres (15-13) had in mind when they arrived at PETCO Park on Wednesday for the final game of a six-game homestand, although it's the burden they bear before hitting the road.

Hensley allowed one run over the first two innings Wednesday against the Nationals (9-19), and he appeared to be settling into a groove when the injury occurred to start the third inning.

Hensley got Washington leadoff hitter Felipe Lopez to ground a foul ball on the right side. As normal protocol for a pitcher, Hensley's first reaction was to bolt from the mound to cover first base. That's when the injury occurred.

Hensley immediately pulled up and winced in pain. He wore that same agonizing look a few moments later when, attempting to remain in the game, he couldn't continue after he took one warmup pitch as Black, pitching coach Darren Balsley and head trainer Todd Hutcheson looked on.

Hensley already had dressed and left the clubhouse by the time reliever Royce Ring got the final three outs in the ninth inning. An MRI will be taken on Hensley's groin, though it's not known if he will remain in San Diego to rehab or join the Padres on the road, as catcher Josh Bard -- who spent time on the disabled list with a strained left groin -- did recently.

Hensley -- who began the season with three straight losses and had a 12.21 ERA -- appeared to have licked the blister problems he had on his right middle finger and had been pitching better. He picked up his first victory April 21 at Colorado, allowing two runs in six innings. Then, in his last start, Hensley again pitched well, limiting the Dodgers to two runs in 6 1/3 innings, though he was stuck with a no-decision.

"It's unfortunate," Black said. "It looks as though he had made strides his last couple of starts. He had made a couple of adjustments with Darren on the mechanical side, and it looked like his confidence was growing."

The Padres now have some decisions to make.

First, they're likely to recall a relief pitcher from Triple-A Portland in time for the start of the series against the Marlins. Second, and of more importance, they'll need a pitcher who can fill in for Hensley for what should be at least two starts.

The most obvious candidate is right-hander Justin Germano, who is 4-0 with a 1.69 ERA for Portland. Germano tossed eight shutout innings against Fresno on Tuesday. He struck out five and didn't walk a batter. Better still, if he indeed is the pitcher recalled, he would be working on six days' rest when Hensley's turn in the rotation comes up Tuesday.

The Padres likely will need another reliever to help aid a bullpen that covered 12 innings in Sunday's 17-inning loss to the Dodgers and seven more on Wednesday. The team gets a day off Thursday, though even that won't bring them to full strength.

San Diego's bats made sure this game didn't push past nine innings, as the Padres jumped on Nationals starter Matt Chico (2-3) for five runs in the fourth inning. Second baseman Marcus Giles, who missed the prior two games with sore ribs, celebrated his return with a two-run single in the inning.

Adrian Gonzalez added a solo home run in the eighth inning, his eighth of the season, and Terrmel Sledge drove in another run later in the inning with a double. Giles had two hits, driving his average up to .330.

"It felt good to get a few at-bats, so I don't feel naked on Friday," Giles said. "It feels great to be back in with the guys. Being on the bench ... it is something you don't want to do."

That's something Hensley will discover soon enough.