Former Chelsea schoolboy, Olise was among the players on the standby roster and it was logically thought that he would be added to the main list following the spate of withdrawals that hit the squad.
Spanish-based duo Kenneth Omeruo and Sadiq Umar were prevented from traveling to Africa as a result of coronavirus concerns and the same applied to French Ligue 1 stars Moses Simon, Simon Kalu and Terem Moffi.
Olise has played non-binding games for France at youth level, and also qualifies to represent Nigeria through his father as well as England.
“Michael Olise is a player we put on the standby list but he could not come because finally there were some restrictions and he could not travel, like other players,” Rohr said to Elegbete TV Sports.
“You know the French players have not been released, some Spanish players have not been released the last time – Omeruo, Sadiq Umar.
“In France we had Kalu, Moffi could not come, that’s why I took in the last moment local players to replace them.”
Olise is having an outstanding season at Reading with a goal involvement of 16 (6 goals, 10 assists) in 41 appearances in the Championship, and continues to be linked with Premier League clubs ahead of the summer transfer window.