Treinen was absent from camp Tuesday due to a family issue, Fabian Ardaya of The Athletic reports.
Treinen previously reported to camp and is expected to return Wednesday, according to manager Dave Roberts, so this doesn't appear to be an issue that will affect his readiness for Cactus League contests. The right-hander is tentatively expected to serve as the team's closer unless Kenley Jansen, who remains a free agent, is brought back into the fold.