United made enquiries after the Uruguay international over the summer before an August injury ruled him out for the first-half of the season.
Araujo has only just returned to action for Barca and Sport says United remain interested.
It's been suggested Barca want €50m for Araujo, who confirmed last week talks over a new deal were underway.
Meanwhile, Araujo's agent has confirmed an attempt from Juventus this week for his client.
Andres Espinosa told Mundo Deportivo: "He has received several offers this January, the most important of which from the Bianconeri.
"But he hasn't made a definitive decision yet because he gives priority to the Blaugrana."