Considering that Chase Lucas did a good overall job on Special Teams for the Lions (even factoring in one of the key plays NFC Championship game in SF that led to the Lions losing the game), that Lucas has versatility as a CB, and the ultra-low cost of a ERFA Tender, I'm somewhat surprised that the Lions didn't tender Lucas. My guess is the reason for the decision is the Lions have seen enough of Lucas to determine (in the opinion of the team brass) he doesn't have enough upside potential and value as a player to bring him back to compete for a 53-man roster spot. I think another NFL team will end up giving Lucas an opportunity this year.
The Lions could have retained Lions retained Chase Lucas with a ERFA Tender Offer. It's hard to imagine that the Lions had interest in re-signing Lucas not long after he wasn't tendered as an ERFA. An ERFA has less than a $ 1 million salary number.