The defender missed the Super Eagles' final training session at Essentuki Arena on Thursday afternoon - before they travelled to Kaliningrad. And it was reported that the Brighton and Hove Albion new signing underwent scans.
Responding to questions as regards the fitness of his squad, Rohr admitted that, although he has a healthy pack of 23, the Germany-born defender's inclusion in their 2018 Fifa World Cup opener against Zlatko Dalic's side is in doubts.
"We have 23 players who are very fit," Rohr said at the pre-match conference.
"When we started our preparations against Congo three weeks ago, it was hard, some didn't play much, others didn't have rest in winter time because they play in England. But we had a good programme.
"Now we have a little injury, Leon Balogun, we will see tonight how he is.
"He is 50-50 at the moment, and we will decide tomorrow. We are ready, mentally, physically. We know they have good players that we saw in the final of the Champions League and in the final of the Europa League."
Balogun was unlucky to miss out on Brazil 2014 due to an injury and will be hoping to overcome his recent misfortune to play against the Fiery Ones on Saturday.