Mourinho warned: "He's injured and I think we need to get used to it.
"Last season he was already in this type of situation and this season he will probably have more of that."
On United's performance, Mourinho added: "We are not a team. We're a group of players from different teams.
"Some are first-team, some under-23s, some coming from loans and going on loan, some are younger, under-18s. We don't have a team to play much better than we did but (it's) one more training session."