Sources said the Detroit Lions remain optimistic about Ndamukong Suh staying and are very enthused about his start to the season.

But there is a growing sense in conversations with numerous execs and agents around the league, including many who have been in contact with Suh's representatives, that striking a deal prior to the start of free agency will be very difficult.

Suh counts $22.4M against the cap this season and franchising him for one year, at around $27M, isn't feasible for the Lions, sources said.