LOS ANGELES -- Bryce Harper should be back in the Phillies' lineup on Friday.

Jean Segura might not be back until July.

The Phillies cannot afford to lose either player for even a day, but neither of them were in Wednesday night’s lineup against the Dodgers at Dodger Stadium. Both left Tuesday’s game because of health issues. Harper tweaked his lower back on a swing in the fourth inning. He is day to day. Segura sustained a Grade 1 left groin strain running to first base in the ninth. He is on the 10-day injured list.

“I had a little spasm on that swing,” Harper said Wednesday. “I woke up a little sore this morning. I could have played today, but everyone wanted to give me another day off so that I have two days off. I should be good to go by Friday.”

Segura, however, could miss roughly three weeks.

“Jean recovers well,” Phillies general manager Sam Fuld said. “He’s feeling better today.”

Harper is batting .274 with eight home runs, 18 RBIs and an .857 OPS. He was 6-for-15 with one double and three RBIs in his last four games before he got hurt. It is the second time this season Harper cannot play because of a lower back issue.

It is an issue that slowed him considerably the final month of last season, too.

The Phillies and others maintain there is no cause for alarm, but the concern about Harper’s back is understandable considering he is 28 and in the third year of a 13-year, $330 million contract.

“I think you get smarter as time goes on and you realize how to deal with it better and better,” manager Joe Girardi said. “I hurt [my back] when I was 26. And I played until I was 39. It’s maintainable. … I think you know it’s unpredictable, but it’s not like I sit around thinking, 'Is it going to happen today?' I just roll him out there and say, 'OK, he’ll be good.'”

Segura is batting .332 with three homers, 20 RBIs and an .845 OPS. Girardi on Monday stumped for him to make the National League All-Star team. Now, the manager might be without his most consistent hitter for a few weeks.

“It’s significant because Jean was playing at an extremely high level,” Girardi said. “He was doing everything -- getting on base, stealing bases, scoring runs, driving in runs, playing really good defense. He was leading our infield. He was a veteran out there. It’s a substantial loss. We just need some guys to step up a little bit and perform.”

The Phillies will play Luke Williams, Nick Maton and Brad Miller at second base while Segura is sidelined. Miller started in right field on Wednesday.

But at least Harper should play on Friday at Oracle Park in San Francisco. The Giants pushed hard to sign him a few years ago, but the Phillies came over the top and signed him instead.

It is not a series Harper will want to miss.

“Oracle is Bryce Harper’s friendly confines,” Harper’s agent Scott Boras said.