The Nigeria striker faces his former club in a re-arranged Premier League clash tonight having signed on loan for Birmingham from Russian club Rubin Kazan until the end of the season.
And Martins, 26, a Toon favourite until they were relegated in 2009, said: "I have good memories with the fans and the players.
"I left because they couldn't afford the money. The club asked me to go and called me when Wolfsburg came in.
"We had good players but things weren't right and even we didn't know ourselves why we were relegated. I don't know what reception I'll get."