The Aston Villa defender spent time at Ibrox a few years back and now manager Ally McCoist is keen to get the Aston Villa man back to Glasgow with owner Craig Whyte confirming there was a second bid for the Spaniard.
He also confirmed that 'Gers do have some other players they are tracking.
"Ally has offers in for several players," he said.
"We have an offer in for Carlos and are still discussing it with Aston Villa. I think there is a deal to be done.
"We have also spoken to Hearts about Lee Wallace. We have our valuation of the player and they have theirs but we will see if there is something that can be done."
It is believed that Rangers made an opening offer to Villa of around £1.5million which was rejected, however, they might have a deal if the new bid is closer to £2.5m.