Clubs have two weeks left to make any loan signings before January and Keane is wary of having too many players not involved.
Speaking at the Ipswich Town supporters' club's annual general meeting, he said: "There are no imminent loan signings and I may look to the transfer window opening in January now.
"I have no complaints with the owner and chief executive over the backing they are giving me but I made a mistake at Sunderland in overloading my squad.
"Having two or three unhappy players is okay but seven or eight ganging up can have its problems.
"I have to be realistic and perhaps look to letting players go before I can bring some in."