Four Detroit Lions players opened training camp on either the physically unable to perform (PUP) list or non-football injury (NFI) list, preventing them from taking part in Day 1 of practice. There is some good news, though: Two of those players, running back Joique Bell and right tackle LaAdrian Waddle, got some work in with trainers off to the side.
Tim Twentyman reports that both Bell and Waddle ran with trainers, and Mike O'Hara reports that Waddle hit the blocking sled in a "solo drill." If nothing else, this is an indication that Bell and Waddle are far enough along in their recoveries from offseason surgery to work with trainers. Typically, when players are able to do that, they return to practice not long after, but it remains to be seen if that will be the case with Bell and Waddle.
As for defensive end Jason Jones (PUP list) and defensive tackle Haloti Ngata (NFI list), they didn't do anything during Monday's practice, according to Kyle Meinke. Dave Birkett did note that Ngata had "no discernible limp" despite being sidelined by a minor hamstring injury, so that's a positive sign and some confirmation that his injury is indeed merely minor.