Christopher Long is among 16 first-team players who have been confirmed as leaving Motherwell.
Long, who has scored 17 goals in two seasons at Fir Park, is leaving at the end of his contract along with Aaron Chapman, Sam Foley, Ross MacIver, Liam Polworth, Harry Robinson, Sherwin Seedorf and Jamie Semple.
The departures of Aberdeen-bound skipper Declan Gallagher and midfielder Allan Campbell had already been announced.
Loan players Jake Hastie, Liam Kelly, Tyler Magloire, Eddie Nolan, Jordan Roberts and Harry Smith are also going back to their parent clubs but one or more could return.
The club added that Devante Cole, Dean Cornelius, Charles Dunne and Scott Fox had all been either offered contracts or invited back for pre-season training.
Cole shelved contract talks until after the end of the season while Dunne has recently returned from a long-term injury.
Fox is yet to make his Motherwell debut after suffering a knee injury early in his Fir Park career but played twice for Morton in the play-offs after joining on an emergency loan.
Manager Graham Alexander told the club's official website: "We not only remain in positive discussions with some of our players but also with a number of clubs in relation to one or two players we had on loan, with a view to doing something. But these things take some time.
"The process of rebuilding the squad is well under way."
