Ba had been set to join the Potters from German side Hoffenheim in January 2011, but failed a medical and the deal fell through.
Tony Pulis: "We have a medical team here who made a decision and they are fantastic - you only have to see the number of times we get various people on the pitch and what we get out of our players.
"They don't need any backing up. They thought there was a problem there - fine, we'll get on with it.
"Both of them (Ba and Cisse, who has 10 goals in nine games for Newcastle) have done brilliantly, and good luck to them. I don't wish them any harm at all - except for when we play against them!
"Let's not forget that there were a hell of a lot of Newcastle supporters who didn't want Alan there and were moaning and complaining.
"It is a good job the chairman didn't take any notice of them, because he has done fantastically.
"I'm pleased for him because I think universally it was accepted that he wasn't the right man for the job initially.
"It is always nice when a manager can prove people wrong, Alan has done that up there and now the supporters love him."