Connor, who only scored seven goals during his two-and-a-half-year spell at the club, was told at the end of last season that he could look elsewhere, but that the door was not completely closed on him.
He will now return to the club for training this week and Allen believes he is the kind of player the club needs.
Allen told the Citizen: "I am still considering him (Connor) because he was a diamond towards the end of the season.
"In one game he played on the right wing, got cramp with about 10 minutes to go and he got a standing ovation from the whole ground for running his heart out. That's the sort of people we are going to need.
"I want people who have full commitment to our squad and who can adapt to different positions without sulking or moaning. He was magnificent, so we will see how it all pans out."