The former Scotland captain suffered a broken rib in the Carling Cup final triumph over Arsenal in a challenge with Samir Nasri.
Ferguson has continued to play by taking pain killers for the past six weeks and has remained a key figure in the battle for Barclays Premier League survival.
But now boss Alex McLeish is confident Ferguson is over his setback ahead of Saturday's home clash with out-of-form Sunderland.
"Ferguson has his rib problem and was taking big injections to play," said McLeish.
"But he is good now, feeling like brand new. Barry said he still gets the odd twinge but he is pretty much over it."
McLeish has an open mind over the theory that British players, like Ferguson, are more prepared to play when less than 100% fit than foreign stars.
He said: "I have played with players at Aberdeen and we started bringing foreigners into the team. They were great players but they wouldn't play if they weren't 100%.
"I am not blaming the foreigners for that. They are great players and they don't take some of the chances we do.
"But maybe we are the daft ones - us Brits. I always remember going through it myself, playing when not 100%, and thinking 'I wish I hadn't played today' if I had a nightmare."
Meanwhile Blues winger Sebastian Larsson has still to make his mind up over where his future lies after this season. The Swedish international can leave Blues on a free transfer in the summer if he so desires when his contract runs out.
McLeish said: "Seb is in a comfortable position just now. He knows he can dictate what he wants to do in the summer and that's the way it has always been.
"I have asked Seb to keep his powder dry until the end of the season. Everything will take care of itself in the summer and Seb said to me he had not made up his mind."
Source: PA
Source: PA