The Magpies were plunged into another farce on Monday night when unpopular director of football Joe Kinnear resigned his post. Only two players came in on loan during his eight months at the club.
But Shearer told talkSPORT: "Joe Kinnear was quoted as saying no-one would be leaving Newcastle in the January transfer window. The rumours were there about Cabaye for months beforehand. They only just managed to hold on to him despite reported interest from Arsenal in the previous window.
"Having said all that, there's only guy who can make those decisions. It's not the director of football or the manager, it's the guy [Ashley] who signs the cheques."
He added: "If you're going to let your best player go, you have to have a plan for someone to come in. You can't let him [Cabaye] leave and then bring no-one else in. That just can't happen."
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