Upcoming key NFL dates for the Detroit Lions:

— Feb. 17-23: NFL Scouting Combine, Lucas Oil Stadium, Indianapolis.

— March 2: Prior to 4 p.m., deadline for clubs to designate franchise or transition players.

— March 7-10: Clubs are permitted to contact, and enter into contract negotiations with the certified agents of players who will become unrestricted free agents upon the expiration of their 2014 contracts at 4 p.m., on March 10. However, a contract cannot be executed with a new club until 4 p.m., on March 10.

— March 10: Top-51 begins. All clubs must be under the 2015 salary cap prior to 4 p.m.  All 2014 player contracts expire at 4 p.m. The 2015 league year and free agency period begin at 4 p.m. 

— April 20: Clubs with returning head coaches, like the Lions, may begin offseason workout programs.

— April 24: Deadline for restricted free agents to sign offer sheets.

— April 30-May 2: NFL Draft, Chicago.

(Follow @PaulaPasche on Twitter. Order her book,  “100 Things Lions Fans Should Know & Do Before They Die’’ here. It’s also available at bookstores.)