This will bring to an end an incredible 13-year association with ’Well for Campbell, who played in the youth team between 2008 and 2016 and has made 162 first team appearances since 2016, scoring 16 goals.
The Glasgow born ace – tipped to move to the English Championship – has also made 24 appearances for the Scotland under-21 team.
Alexander said: “I had one last shot a couple of weeks ago (at getting him to stay).
"We did offer him a very good contract for us because I didn’t want to get to the summer and he goes elsewhere and we haven’t tried everything to keep him because he’s a brilliant player, brilliant professional. And any manager would be desperate and keen to keep him on board.
"And I know the reasons why and I can understand the reasons why as an ex-player myself. We had a great chat the other week and he was honest as he always is, and I can see his perspective.
"He’ll be leaving in the summer and I hope he gets the best club he can. Everyone at Motherwell – not only myself – would wish the best for Allan because he’s been absolutely fantastic for this club.
"I think he can go all the way. Not right now, he’s still young, he’s got loads of experience, he’s still got little bits to improve in his game.
"But if I know anything about Allan Campbell he’s going to do everything he can to improve.
"Already he’s a quality player but as you go through the levels you have to find that little bit extra and Allan Campbell will search for that little bit extra and get it.
"Nothing would surprise me in what Allan Campbell goes on to achieve in the next 10/15 years.”