Souness said United's strength in depth means few will feel sorry for Mourinho.
"Every manager wants more and better players, but Jose Mourinho is not going to get too many sympathy votes from English football," Souness said.
"You can go out and spend £200m on two players, I don't think too many people will be feeling sorry for him tonight, that two big players were missing.
"It's Man United after all. United are one of the biggest, richest clubs in the world, if not the richest club in the world.
"They carry a big squad, they're in all the competitions, but that is the price on the ticket. Injuries come along to everyone during the season. It should affect him less than anyone else.
"His complaints, or playing for sympathy, will fall on deaf ears, because it's Man United and they have a great, big squad filled with top players.
"I don't see where he's coming from with that argument."