PHILADELPHIA -- Rhys Hoskins joined the Phillies this week because Aaron Altherr is expected to be on the disabled list until September with a strained right hamstring.
Altherr's injury opened a spot in left field. Hoskins, who is a first baseman, learned left field in less than a week.
The Phillies are eager to get a look at Hoskins, their No. 6 prospect, but losing Altherr is a blow. He had hit .285 with 20 doubles, four triples, 16 home runs, 49 RBIs, an .894 OPS and a 133 OPS+ in 336 plate appearances before the injury. He had been on pace to finish with the highest OPS and OPS+ for a Phillies hitter (minimum 502 plate appearances) since Jayson Werth (.921 and 144) in 2010.
"I'm definitely happy with the season I've had," Altherr said. "But I always go into every Spring Training fighting for a job. You can never get too comfortable in this game. You've got to keep fighting and keep putting up numbers."
If Altherr is not a lock to be an Opening Day outfielder for the Phillies next season, he is a heavy favorite. In fact, the Phillies' Opening Day outfield might be set already with Altherr, Odubel Herrera in center and Nick Williams in right. Herrera's 1.9 WAR since the All-Star break is the best in baseball, according to FanGraphs. Williams has impressed in 135 plate appearances entering Friday, posting an .858 OPS.
Phillies outfielders entered Friday 12th in baseball with a .776 OPS, which includes Michael Saunders' .617 OPS in 214 plate appearances. It is their highest ranking since 2011, when they were ninth with a .774 OPS. It is their highest OPS since 2010, when they ranked fourth with an .821 OPS.
"We've had a lot of talent in the organization," Altherr said. "It was just a matter of time before we started getting good again. I think there are exciting times in the future."
Altherr said he hopes to be back as early as late August or early September. Whenever he returns to action, Hoskins is expected to play more first base. Hoskins hit fourth Friday against the Mets in his second big league game.

"He's not scared," Phillies manager Pete Mackanin said about Hoskins. "There's no fear. He's very confident. He knows he can hit and I don't think it will affect him one bit."
Alumni weekend
The Phillies will honor their Wall of Famers before Saturday night's game: Steve Carlton (1989), Mike Schmidt (1990), Larry Bowa (1991), Dick Allen (1994), Greg Luzinski (1998), Garry Maddox (2001), Tony Taylor (2002), Bob Boone (2005), Juan Samuel (2008), John Kruk (2011), Mike Lieberthal (2012), Charlie Manuel (2014) and Jim Thome (2016).
The Phillies also will have a video tribute for Jim Bunning, Dallas Green and Darren Daulton, who all passed away this year.