The controversial midfielder lasted just eight games in Glasgow before he was frozen out following a row with boss Mark Warburton and team-mate Andy Halliday.
The 34 year old told talkSPORT: "I've got an enormous amount of respect for Rangers as a football club, the fans, the tradition - everything that it stands for.
"I ain't going to come on the radio and have a go and air my dirty laundry in public about Rangers.
"It's just not something I aspire to do. It's not something I'm going to do today, in two months, in 10 months or in two years.
"I'm focused on Burnley. I've got N'Golo Kante and Chelsea on Sunday afternoon. I've got to use every bit of energy I've got trying to turn in a performance against arguably the best player in the league.
"I can't focus on what's going on in Scotland - that's not my bag any more. What's happened, happened."