Philadelphia Phillies slugger Bryce Harper isn't expected back in right field until late July or early August.

However, because the designated hitter was instituted in the National League this season, the reigning Most Valuable Player could be back in the lineup as early as Thursday when the Phillies play the rubber game of a three-game series against the visiting San Diego Padres.

Harper received a plasma-rich platelet injection Sunday in Los Angeles after sustaining a small tear in the ulnar collateral ligament in his right elbow. The Phillies are 1-2 without Harper since he received the injection.

They lost Sunday against the Dodgers and Tuesday against the Padres before responding with a 3-0 win over San Diego on Wednesday.

Before his recent absence, Harper was one of the hottest hitters in the majors, as he went 8-for-12 with three homers and eight RBIs in the first three games against the Dodgers.

Phillies manager Joe Girardi is optimistic that Harper will return to the outfield before the season ends.

"Our hope is that isn't the case," Girardi said of Harper being unable to go back out in the field this year. "Our hope is that the procedure we did helps it scar over and he's fine. It's worked before, but there's no 100 percent guarantee."

The Phillies got enough offense in Harper's absence on Wednesday, as Rhys Hoskins smacked a solo home run, walked and scored two runs. Hoskins hit leadoff, a role that has been held by numerous Phillies so far this season.

"It's different," Hoskins said in a postgame interview on NBC Sports Philadelphia. "Especially the first at-bat of the game."

The Phillies will hand the ball Thursday to Kyle Gibson (3-1, 4.10 ERA), who struggled mightily in his latest outing on Friday against the Dodgers. He allowed eight hits and six runs in 3 2/3 innings.

Gibson is 2-0 with a 2.84 ERA in three career starts against the Padres.

After an impressive 3-0 win in the series opener, San Diego simply couldn't generate any offense on Wednesday against Zack Wheeler.

The Padres will look to Yu Darvish (3-1, 4.62 ERA) to reverse their fortune and come up with a series victory.

Darvish is also coming off a rough outing, as he allowed nine hits and five runs in 5 2/3 innings against the Atlanta Braves on Friday.

"I focused on my big slider," Darvish said after the start. "They were able to hit some fat breaking pitches, but there weren't too many hard hits. I was happy with my game."

Darvish is 1-1 with a 2.30 ERA in five career starts against the Phillies.

Darvish will need more offensive production than just the four hits the Padres managed on Wednesday. Jake Cronenworth had a double for the only extra-base hit, and the Padres had just one at-bat with a runner in scoring position.

Nick Martinez, however, gave San Diego a much-needed spark out of the bullpen with four scoreless innings. Martinez allowed two hits, walked none and struck out six a day after Padres reliever MacKenzie Gore tossed three shutout innings.

"He's good when he attacks the zone," acting manager Ryan Christenson said of Martinez. "When he's doing that, he's really good. He threw the ball extremely well."

The bullpen as a whole wasn't considered a major strength heading into the season, but the recent results have been a pleasant surprise.

"It's just their competitive nature," Christenson said of Gore and Martinez. "They want to stay here. They want to be a contributing force."