O’Neill has made him first choice on the left of midfield despite his relative inexperience.
But, after a positive start to the Premier League season that saw him increasingly involved in first-team affairs at St James’ Park, Ferguson found himself left in the cold by the influx of signings from France in January.
Ferguson eventually agreed a loan deal with Birmingham.
He has earned rave reviews in his four games to date and provided the assist as Blues beat Middlesbrough 1-0 on Saturday.
Gazza once described him as "the best Newcastle prospect in twenty years".
Michael O’Neill: “It was important to get Shane out on loan and I was pleased he got that opportunity.
“The introduction of the new players at Newcastle made things very difficult and sort of halted the progress he was making there.
"He had been getting game time and making an impact, whether he was starting games or coming off the bench.
“At times he hasn’t been playing as much as you would like to give him the best chance of performing for us and going to Birmingham will help that.”
Source: Newcastle United Mad