McCaffrey (undisclosed) isn't participating in Tuesday's joint practice with the Titans, Cam Inman of The San Jose Mercury News reports.
McCaffrey was held out of drills Monday due to what the 49ers termed "tightness," and offensive coordinator Klay Kubiak later touched on the subject, stating the team is "just managing" the veteran running back as he deals with some soreness, per Nick Wagoner of ESPN.com. McCaffrey now is one of four San Francisco running backs tending to an injury -- also Jordan James (broken ribs), Kaelon Black (adductor) and Isaac Guerendo (pectoral, PUP) -- meaning Patrick Taylor, Sincere McCormick and Khalil Herbert are the current healthy options at the position.