Defensive line coach Jim Washburn wasn't the only person back at practice for the Detroit Lions on Monday. In addition to Washburn, the Lions saw the return of three players, according to Tim Twentyman:
CB Darius Slay, WR Calvin Johnson and CB Alex Carter all back at Lions OTAs Monday.— Tim Twentyman (@ttwentyman) June 8, 2015
Darius Slay missed last Thursday's practice because of "self-inflicted" bruised hands. It's still unclear what exactly Slay did to sustain that injury, but clearly it was nothing serious with him already back at practice.
As for Calvin Johnson and Alex Carter, they were absent from practice for non-injury reasons. Johnson simply wasn't in attendance -- OTAs are voluntary, after all -- and Carter was presumably busy finishing up his classes at Stanford. NFL rules bar rookies from taking part in OTAs and the like if they aren't done with school, so Carter had been unable to practice as a result. Now, though, with Carter out on the field, the Lions have their entire rookie class eligible to participate in practice.