MILWAUKEE — Aaron Altherr was one of the brighter spots for the Phillies in an otherwise dismal first half, leading the team with 35 extra-base hits.

And two at-bats into the second half of the 2017 season, the 26-year-old showed no signs of slowing down.

Altherr hit a pair of doubles but left the game after his two-bagger in the fifth with what the team described as a mild strain of the right hamstring. He is considered day to day, manager Pete Mackanin said after the Phillies’ 9-6 loss at Milwaukee Friday night (see Instant Replay).

"I don't know how severe it is," Mackanin said. "If it's mild, it's a day or two. We won't know for sure until tomorrow."

Altherr said he felt the leg pop slightly as he rounded first base and immediately thought to ease up on the leg. The Phillies’ trainer checked him out at second and the decision was made to pull Altherr from the game.

"I felt something biting and felt like if I had ran harder, I'd make it worse," Altherr said. “Kind of shut it down a little bit, figured I shouldn't push it. I think it helped a little bit doing that. I felt a little tweak there with the hamstring. They wanted to play it safe and take me out.

"Right now, I'm pretty much day to day. We'll see what happens.”

Altherr batted .284 during the first half and is a .243 hitter with 23 home runs, 88 RBIs and 18 stolen bases over the last 2½ seasons with the Phillies.

Mackanin had moved Altherr into the leadoff spot for the second time this season but should he need to miss extended time, would likely turn to Daniel Nava to top the order.

"Hopefully it’s going to be a mild strain and he'll be back in a few days," Mackanin said. "If he isn't, we've got Nava who can lead off. He seemed to like that leadoff spot. We'll have to wait and see and find out tomorrow."