The big centre-back took just two reserve games to convince boss Paatelainen he can operate at SPL level.
By agreeing a 15-month contract the former Gretna player has secured for himself another season in the top flight, after making just one substitute appearance so far in this campaign.
Gretna stressed he had left them because a long-standing ankle problem meant he would not be a regular, however Paatelainen believes the defender still has plenty to offer.
And Canning, who joined Gretna from Ross County in 2006, is determined to put the injury nightmare behind him as he rebuilds his career at Easter Road.
"I had the problem for a few years and it got to the point where I had to do something about it," he told the Hibs website.
"The injury happened before my move to Gretna but was not as serious until recently.
"I never played much in the Second Division and I rested throughout the summer to come back fit for the start of the following season.
"It was not quite right though, and during the opening game against Hamilton (last season), I felt it again.
"But I was eager to play, so we basically just strapped it up to get through the season and thankfully it was never too much of a problem.
"I went to see the surgeon at the start of this season and he thought that there was a hole in my tendon.
"He had a look inside and found out that the ligaments had actually snapped."