The Black Cats almost managed to claim a point against the Champions of Europe at Old Trafford.
He said: “We stuck in there, we were under severe pressure the whole game.
“Credit to the players, I thought we showed a good spirit, we worked ever so well and, on top of that, after Thursday’s episode (Keane’s departure), the attitude was first class.”
Sbragia is acting manager at the club after Roy Keane resigned earlier in the week.
“It’s been very tough because it came as a massive surprise,” he said. “A lot of the players obviously came to the club because of Roy.
“We were disappointed. All the staff were disappointed and it came as a shock.”