Nelson experienced some groin soreness during his bullpen session this weekend, Ken Gurnick of MLB.com reports.
Manager Dave Roberts termed the soreness as "benign," so it doesn't appear to be a serious concern. Nelson joined the Dodgers on a one-year deal in January and is looking for a rebound season after posting a 6.95 ERA in 22 innings last year for the Brewers in his return from shoulder surgery.