Speaking of his decision, Rush said; "Ulster are a great team with a bright future. I was very impressed with the set up when I visited and I wish them the best of luck for the forthcoming season."
"However, a change in my personal circumstances has resulted in me deciding to recommit with what has become my home from home, with the Cardiff Blues, where I am very happy."
"I would like to thank all parties concerned for their patience and understanding regarding this matter and now just want to concentrate on having a good pre-season ahead of what promises to be another challenging, but hopefully successful campaign."
Cardiff Blues CEO, Robert Norster added, Xavier has played an integral part in our progress since joining the team in 2005. We are all obviously delighted that he has decided to re-sign and continue his impressive career with the Blues as we look to build on the success of last season."