Dodgers notes: Howie Kendrick, Justin Turner, Bryce Harper, Chris Hatcher

LOS ANGELES -- The Dodgers try to snap a four-game losing streak on Tuesday night against the Nationals, and here is an update on several injured players, including Howie Kendrick, Justin Turner, Bryce Harper and Chris Hatcher.

We don't have official MRI results for Kendrick's left hamstring strain, only that his disabled list stint is expected to last longer than 15 days.

"We know he's going to miss a bare minimum of three weeks," manager Don Mattingly said on Tuesday.

Turner took batting practice at Camelback Ranch in Arizona on Tuesday and is now on his way to Los Angeles. But he isn't expected to be activated before Wednesday's series finale against the Nationals.

Mattingly said Turner will be reevaluated by team doctors before determining when he is activated from the DL.

Alberto Callaspo gets the start at third base on Tuesday night, his 22nd start of the season and eighth in 13 games since Turner was placed on the DL. But what makes tonight stand out is Callaspo hitting second, the first time he has batted higher than sixth all season.

"It's just because of this matchup," Mattingly said about facing Nationals rookie Joe Ross. "He kills right-handers."

The switch-hitting Callaspo does have a .343 on-base percentage batting left-handed this season, including .359 with the Dodgers. Ross, he of the ridiculous 47 strikeouts and just four walks in his 45 major league innings, has yet to allow an extra-base hit against a right-hander this season, holding them to .161/.179/.161.

Harper is out of the Nationals lineup with left knee soreness, with old friend Clint Robinson starting in his place in right field.

Harper was scratched with a sore left knee. He banged it on a dive yesterday but finished game. No MRI, per MW.

— James Wagner (@JamesWagnerWP) August 12, 2015

Harper reported swelling in knee today & will rest to get it out. Available off the bench, per MW. Also hopes Harper can play tomorrow.

— James Wagner (@JamesWagnerWP) August 12, 2015

Mattingly also said that relief pitcher Hatcher would be activated close to Friday, the first day Hatcher is eligible to return from the 60-day disabled list.

"We like Chris," Mattingly said.

Hatcher is 1-4 with a 6.38 ERA this season, but also a 3.21 FIP, with 19 strikeouts, seven walks and one home run allowed in 18⅓ innings. He is currently on a rehab assignment with Triple-A Oklahoma City.

Game info

Time: 7:10 p.m. PT

TV: SportsNet LA