The Dodgers recalled Chris Heisey from Triple-A Oklahoma City on Tuesday.
Just in the first two months of the season, the Dodgers have lost three outfielders, two starting pitchers and three late-inning relievers to injury.
Among the outfielders, Yasiel Puig (left hamstring) is rehabbing in Arizona and is expected to begin a minor league rehab assignment later this week. He could be activated at some point next week. Carl Crawford (torn right oblique) is on the 60-day DL and ineligible to return until June 27, but will probably require more time than that.
Van Slyke, 28, has been a key contributor the past two seasons, mostly playing against left-handed pitchers. He was batting .264 with two home runs and 14 RBIs in 34 games this year. He missed four games with back discomfort before playing Saturday in St. Louis and having the pain crop up again.
Dodgers manager Don Mattingly said doctors didn't find any major structural damage after reviewing an MRI and are treating it as muscle inflammation.
"They didn't find anything devastating. We thought he was good to go then it just cropped up again and we felt we had to get somebody up here," Mattingly said.
The Dodgers heard good news about injured reliever Paco Rodriguez. Tests showed no structural damage to Rodriguez's left elbow and team doctor Neal ElAttrache diagnosed him with tendinitis. The pitcher will rest for a few days and then begin his throwing program.