Phillips, 33, rejected a return to Wearside and made the decision to stay in the Midlands where he and his family were settled.
"I had some great times there and had the opportunity to go back but chose West Brom," he said. "My first league game was back there and the reception I got left a bitter taste. It surprised me. I made the decision on family grounds and the fans never respected that.
"They wanted to see me back there but I'd had six great years there and in the back of my mind I thought players who go back rarely recreate what they had before. I doubt [at 33] if I could have achieved what I did before.
"And if I had gone there, I'd have been signing for Niall [Quinn, the chairman who briefly managed the club before appointing Roy Keane] — and he lasted about a week. I think I made the right decision. In an ideal world, both of us would get promoted."
Sunderland take on West Brom today in what is to be a crucial game for the Black Cats. Catch all the build-up and post-match interviews on THEBLACKCATS.CO.UK!