The former Premier League outfit were offered the Portuguese superstar by Sporting Lisbon but the attacker ultimately ended up at Old Trafford
Former Birmingham owner David Sullivan claims the Blues could have signed Cristiano Ronaldo for £6 million (€7.6m) before he moved to Manchester United in 2003.
The Portugal international was signed by Sir Alex Ferguson as an 18-year-old and moved to Old Trafford from Sporting Lisbon in a deal worth €15.5m.
Ronaldo went on to spend six years at United, winning the Champions League and three Premier League titles before signing for Real Madrid in 2009.
However, Sullivan claims Birmingham could have captured the teenager who was offered to the Blues before opting to sign for the Red Devils.
“Before he went to Man United, we were offered him for £6m, and he chose United ahead of us,” he told Sky Sports programme ‘Soccer AM’.
“There was a deal to be done. When he first went to United there were lots of doubts about him. He wasn’t the star that he is now.”
Ronaldo is the current Ballon d’Or holder and the heavy favourite to win this year’s award after firing Madrid to Champions League glory in May.