Clarke had made over 200 appearances for St Mirren since breaking into the side as a teenager at a time when Scottish clubs were capable of competing at a reasonable level in Europe.
In the summer of 1985 West Ham had spent £350,000 to sign Frank McAvennie from St Mirren with Clarke tipped as the next big thing.
Celtic dramatically won the title in season 85/86 but were wrong footed by the big spending of Graeme Souness at the start of the following season- despite winning the title Celtic never added to their squad.
Early in 1987 reinforcements were overdue with Hay identifying Clarke as a home-made addition for his side.
In the Evening Times he recalled: “With Danny McGrain coming to the end of his career, I had identified Clarke as a potential replacement before he went to Chelsea.
“That was the time when I also wanted Pat Nevin and Joe McLaughlin – with Jack McGinn telling the media that if I wanted them I’d be paying for them out of my own pocket!
“In any case, I have always been a fan of Clarke and you have to applaud what he has done at Rugby Park.”
Clarke went on to spend 11 seasons as a player at Chelsea before moving into coaching working alongside Jose Mourinho, Bobby Robson, Kenny Dalglish and others.