De Gea is still the subject of fierce interest from Real Madrid, despite a move for the keeper falling through on transfer deadline day last summer.
French champions Paris Saint-Germain have also reportedly joined the race for the 25-year-old, who signed a new contract with United after the deal to take him to the Bernabeu failed.
The Reds remain hopeful of convincing De Gea to stay at Old Trafford, but with the possibility of United not making the top four and securing Champions League football, there remains concern that he could leave Manchester this summer.
And Barcelona’s number two is seen to be their top target after informal contact between the player and the club revealed that the German could be willing to leave the Nou Camp in the search for regular first-team football.
Ter Stegen currently starts in Copa del Rey and Champions League games for Barcelona, with incumbent Claudio Bravo starting all games in La Liga, and it is this arrangement that seems to be the source of the 23-year-old’s discontent.
Borussia Dortmund are also interested in signing the talented keeper, but the former Borussia Monchengladbach man, who has four German international caps to his name, does not want to return to the Bundesliga, leaving the door open for United to secure his services should De Gea decide to exit.