Sources said that Barca will target players who are not playing regularly for their clubs, with ESPN previously reporting that Manchester City forward Raheem Sterling and Chelsea duo Timo Werner and Hakim Ziyech are also being monitored.
Cavani, 34, is contracted at United until the end of 2021-22 but has made only eight appearances this season following the arrival of Cristiano Ronaldo.
Cavani has said previously he would not rule out playing in LaLiga. However, sources also told ESPN that Cavani plans to consult with Manchester United's incoming interim manager, Ralf Rangnick, on his plans for the striker before making a decision.
Barca CEO Ferran Reverter has confirmed the club will be able to sign players in January, despite their on-going financial situation, but they will have to be clever about how they fund any new arrivals.
The priority, therefore, is to find players that can come for relatively little outlay, ideally on a short-term contract or a loan without an obligation to make the move permanent.
For now, Barca are doing their groundwork ahead of the opening of the window to find out which players are available, affordable and willing to come to Camp Nou.
Cavani, 34, could fit what they're looking for, with sources confirming the Uruguayan striker wants to play more regularly. With Sergio Aguero out indefinitely due to a heart condition, that would be possible at Barca.