The 28-year-old impressed enough during his loan spell at St Andrew's to persuade the club to part with £250,000 in the summer (via Mail) to make his switch a permanent one.
Birmingham's Ryan Shotton
And the former Derby County defender has had no problem replicating the form he showed last term. He has played in every single Championship clash that Birmingham have contested this season, and his form alongside Michael Morrison has been one of the reasons why they currently find themselves fourth in the table.
And reflecting upon his return to the club, Rowett admitted that he was delighted with how good a piece of business the Midlands outfit have managed to secure.
Birmingham’s manager Gary Rowett
"I would say for around a quarter of a million pounds he has been an absolute bargain so far," he said, as reported by the Mail.
"As a pairing they have been excellent, I think they really complement each other. We saw that towards the end of last season.
"I know we still conceded some goals and we knew we needed to improve in that area - but we just felt as though we needed something different."
Birmingham City's Ryan Shotton and Wigan Athletic's Will Grigg in action
Only a handful of sides have conceded fewer times than the 19 occasions that Birmingham have in the league this season, with Shotton helping the team keep six clean sheets along the way.
And if he can continue to provide that steel that makes the Blues so difficult to break down, it will be difficult to imagine Rowett's men not finishing inside the top six come the end of the campaign.