Starters were spectators, including quarterback Derek Carr. No need to risk a freak injury to a key player with more than a month of down time upcoming before the Raiders report to training camp July 28.
"We got a lot of good, productive work in," Del Rio said. "We're looking forward to this little break that we get. I told our guys two things: make sure you're taking care of your bodies so you arrive in camp ready to work.
"Two, stay out of trouble. Be safe. Make good decisions. This time of year, more occurrences happen than ever at this time of year. Just don't take any liberties. Don't take chances. Don't take things for granted. Appreciate where we are and the opportunities we have."
Coming off a 12-4 season and the franchise's first playoff season since 2002, the Raiders are looking to step up, perhaps win the division and move deeper into the postseason all the way to the Super Bowl.
Things addressed during the offseason included giving Carr an increased role in the offense with the freedom to get the unit in and out of different plays, and incorporating new weapons such as running back Marshawn Lynch, tight end Jared Cook and wide receiver Cordarrelle Patterson.
Lynch was eased in and it won't be known how he'll respond to a year off until he begins taking hits again, but his mere presence during the voluntary portion of camp exceeded what he did with Seattle.
Cook appears to be an immediate threat in the middle of the field judging from non-contact work, and Patterson was given a long look as a receiver both short and long as well as someone who can run the occasional reverse.
Defensively, rookie first-round pick Gareon Conley and safety Obi Melinfonwu were immediately put into sub-package situations and will be counted on to develop quickly in training camp now that they've got a background in the system and terminology.
Del Rio is hopeful of having no major injury issues that would preclude players from being unavailable early. Tackle Austin Howard, who had offseason surgery, is being tracked to be ready on July 28. Jon Feliciano, a backup guard and center, was injured during the minicamp and could be problematic.