Of far greater concern for Ferguson will be the condition of Vidic, who limped off after 33 minutes of the tie after he had landed awkwardly, jarring his knee, following an aerial challenge with Roma forward Mirko Vucinic.
Vidic's defensive partnership with Rio Ferdinand has been the foundation on which United's success over the last two seasons has been built. If the Serb is ruled out for a significant period, it would hand a huge boost to Chelsea and Arsenal in the race for the Premier League title.
Ferguson said: "I pray it is not serious because he is an integral part of our team. It might just be a nerve injury but we can't be sure."
With Barcelona having won 1-0 away at German club Schalke in the first leg of their quarter-final last night, a last-four tie between two of the giants of European football appears a virtual certainty.
But after watching his team ride their luck early in the second half when Roma were only a goal down, Ferguson knows it would be foolish to underestimate Spalletti's men.
He said: "It was a fantastic result for us but I will probably start to worry about it on the day of the game.
"The first thing we have to do is prepare properly for the match. We cannot take anything for granted with a place in the semi-finals at stake."
There was no repeat of the violent scenes that have marred clashes between the clubs in recent matches, and the United manager said: "That is a bonus and what we wanted to happen.
"Roma and ourselves worked hard to make sure there would be no incidents."
