O'Toole, 33, arrived as a free agent in October when Stags were in the middle of an injury crisis, and was given a short-term contract until January.
But O'Toole has impressed and helped Stags to a run of six wins in seven and manager Clough said: “I am probably going to have a chat with David Sharpe (club CEO) this week about it.
“Obviously John-Joe has another four weeks or so left, but he has slotted in and done very well indeed.
“We've seen his versatility. He played in midfield against Newcastle, he's played in the middle of a three and he's played at centre half in a two.
“Considering he hadn't played in a few months I think his fitness levels have been a credit to him.”
With experienced James Perch out for the season with a fractured skull, O'Toole has proved to be the perfect replacement.