Coach Jim Schwartz said it's disappointing Suh has missed some opportunities in training camp that are gone forever.
Suh is the former Nebraska defensive lineman who was the No. 2 pick overall in the NFL draft.
The Lions have had only one player, Calvin Johnson, miss more than a couple days since Bryant Westbrook was a long-term holdout in 1997. Westbrook's agents were Roosevelt Barnes and Eugene Parker, both of whom are representing Suh.
"Both sides are working hard to get this resolved," Barnes wrote in an e-mail to The Associated Press.
Suh posted a message on his Twitter account Sunday that quoted a biblical passage: "Judge not by with appearances, but judge with the right judgment."
(This version CORRECTS Corrects name to Bryant instead of Bryan in fourth paragraph.)