The Football Association will investigate an incident between Tyrone Mings and Nelson Oliveira.
Oliveira suffered major facial damage, having to go through surgery.
Reading tweeted after the game saying: "Nélson Oliveira has had surgery and is recovering well."
Mings said on the platform: "Feel awfully sorry to Oliveira, I hope he is ok."
It is not the first incident for Mings, who was suspended for five games for a similar incident with Zlatan Ibrahimovic in the Premier League in 2017.