Rangers are looking to bring Greg Docherty to Ibrox this month.
Celtic's defensive options have been criticised of late.
Rangers playmaker Josh Windass has been linked with a move away from Ibrox.
Celtic have reportedly made a bid for Dusko Tosic.
Rangers completed a deal to bring defender Russell Martin to Ibrox on Tuesday.
Rangers have failed with a bid to bring winger Jordan Jones to Ibrox.
Rangers have secured a deal to bring Russell Martin to Ibrox.
Rangers coach Stuart Taylor is already set to leave Ibrox.
Rangers are reportedly looking to bring Devante Cole to Ibrox.
Rangers are attempting to bring midfielder Greg Docherty to Ibrox.