The 25-year-old French international had agreed personal terms with the club, but the deal was called off when medical tests revealed a long-standing knee problem.

Manager Ruud Gullit wanted Ba to fill the gap left by Keith Gillespie's recent departure to Blackburn Rovers.

"We had a player we had worked very hard to get, but then he failed his medical. On one hand, it's unlucky for us, but at least we haven't lost a lot of money buying a player who maybe couldn't play for a long time," said Gullit.

"It's a very big disappointment. We worked very hard to get him here in secret for his medical. Nobody knew about it - despite his blond hair," he added.

Ruud Gullit 'The criticism hurts' (BBC Radio 5 Live)

Gullit conducted negotiations behind a smokescreen of a trip to Holland to see his family - a story which led to him having to re-state his commitment to the club.

"I think people owe me an apology. I'm not going to tell anyone what I'm going to do," he said.