Steve Bruce has praised defender Kenny Cunningham for Birmingham's upturn in fortunes and claimed "he is getting better with age".
Matthew Upson has received plenty of plaudits for his performances at the back which have seen him converted from an Arsenal reserve to an England squad regular since his January move to St Andrews.
But the steadying influence and know how of Republic of Ireland captain Cunningham has been just as crucial in Birmingham's solid first season in the top flight and unbeaten start to the current campaign.
The Dubliner ended a seven-year association with Wimbledon to move to Birmingham for a cut-price £350,000 sterling in the summer of 2002 and has been a model of consistency ever since.
In fact, City have still to concede a Premiership goal this season in the five Premiership games where Upson and Cunningham have been in tandem.
Bruce said: "There are not many, apart from the elite ones at the top four or five clubs in the country, that I would swap the pair of them for.
"There is a nice balance between them. Upson is young and athletic and willing to learn . . . but he is helped a lot as well by Cunningham who just seems to be getting better with age. He has got that habit of being in the right place at the right time.
"He just reads the game so well. He's got that positional sense. He knows that he is not the quickest or biggest of players. He knows he has to rely on his positional play and intelligence and he does it so well," the Birmingham manager said.
PA