Board Thread:General Discussion/@comment-6747658-20130401084750/@comment-1504072-20130422075509

Old Boy is not mentioned in MGS2, he is only described as being killed off during Dead Cell's liquidation in the game's script. The details of his background are from Hideo Kojima's MGS2 game plan, where he is stated to be over 100 years old during Dead Cell's time. Therefore his exact year of birth is quite vague. However, his article here originally gave it as the early 1900s, assuming that his age was "just" over 100, so I've removed this inaccurate claim.

Therefore, Old Boy could theoretically be 100 by the time of Ground Zeroes. In my opinion though, I don't think they would resurrect such an obscure character.