Okonkwo, a regular fixture in the side under former coach Samson Siasia, was blacklisted by Keshi when he left camp a few days into training under the new coach for an unsuccessful trial in England.
This was after Keshi had decreed that home based players must be ready to stay at least six months with the national team before attempting to travel abroad.
With the Nations Cup approaching, and options limited at right back, Keshi has now recalled the experienced defender saying every person deserves to be given a second chance in life no matter what, but the player must now justify his call-up.
"But he has to prove that he’s a better player in terms of discipline and action on the pitch," he said.
Okonkwo played the second half in the 1-1 draw against Nasarawa United on Thursday and showed flashes of his old self.