The 20-year-old midfielder missed Nigeria's opening game, a 6-1 thrashing of Tahiti, due to a knee injury, but Keshi had expressed optimism he would be fit in time for Thursday's crucial Group B clash with Uruguay.
However, he has now suggested that the Lazio player, who remained in Nigeria for treatment, will be spared the trip to Brazil in order to keep him fresh for World Cup qualifying matches later in the year.
"Up to now, we don't know. I'm not sure if he's coming," Keshi said during Wednesday's pre-game press conference at Salvador's Arena Fonte Nova.
"We're not too much in haste. We have three very important World Cup games in September, October and November.
"Those are more important for us, although of course the Confederations Cup is good for us too. We don't want to push him too much. We want to let him be ready."
Keshi was reluctant to comment on the demonstrations that have swept Brazil since the start of the tournament, with hundreds of thousands of people taking to the streets to protest against mass transit price increases and what they allege is the improper allocation of public funds.
"I think whatever the public are doing is something related to politics and other stuff," he said.
"We keep football apart from politics. I don't think it's something to take the concentration away from football. In Nigeria we try to keep both separate."
Thursday's game will go a long way towards determining which of the two sides reach the semifinals alongside likely group winners Spain, who beat Uruguay 2-1 in their opening match.
Oscar Tabarez's Uruguay boast the attacking might of Luis Suarez, Edinson Cavani and Diego Forlan, who is poised to win his 100th cap.
Keshi described the game as a "final", but he also said that he was not unduly troubled by the prospect of facing the 2011 Copa America winners.
"What I'm most worried about is my team," he said.
"If they can play to the tactical plan that we're working on and concentrate for 95 minutes, then we'll be fine, no problem."
On reports that Uruguay will play with a three-man defence, Keshi said: "What Uruguay are doing is Uruguay's plan. I will have my own plan for Nigeria and we'll see what happens."