Forrester could make his AFC Wimbledon debut against Doncaster Rovers today after joining the Dons on a season-long loan from Glasgow Rangers.
The 26-year-old is understood to have negotiated his own release from Doncaster to join the Scottish giants in January 2016.
He made only two Rovers appearances under Ferguson.
“Harry and I left on fine terms, there was never a problem. I think the boy’s a really good player,” said Ferguson.
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“Anyone who has watched him knows he’s got bags and bags of ability.
“He got a great move to Rangers, a fantastic experience for him.
“New managers have new ideas and a new manager has come in and he doesn’t fit into his plans.
“Whether he plays or not, I don’t know, because he obviously hasn’t played this season. I don’t know what level of fitness he is at.
“If he does, the players will know him and he can open you up at any second. He’s got that ability.
“I don’t think he would have any [extra motivation against Doncaster],” he added.
“He may have, I don’t know. Certainly me and him never had a problem. In fact he would really suit the way that we play but at the time he was’t getting enough game time.”