Rangers's demotion to the Scottish Third Division due to their financial problems has led many observers to claim that the SPL has become a one-horse race.
Neil Lennon's side are currently 15 points clear at the top of the table and Mulgrew has said that Celtic do miss the Old Firm rivalry with their Glasgow neighbours.
When asked if he would like to see Rangers back in the SPL, the Scotland international told Sky Sports News: "If it was my choice? Probably, yes.
"I don't want to get involved in what's going on with that side of things, I'm just concentrating on things at Celtic. Hopefully things will work out for the best."
Rangers are currently 17 points clear at the top of the Scottish Third Division.