Neither club has yet submitted a formal offer for the 22-year-old.
Eintracht Frankfurt signed Larsson from Malmö FF in the summer of 2023, and he immediately established himself as close to a guaranteed starter, form that has seen him repeatedly linked with a fresh move in the years since.
Earlier this month, transfer expert Fabrizio Romano reported that a transfer was under consideration for Larsson ahead of next season, with several clubs said to have made enquiries about the midfielder, though their identities were not disclosed at the time.
Bild's report now points specifically to Manchester United and Newcastle United as the clubs showing the most concrete interest heading into the closing weeks of the transfer window. Larsson's contract with Frankfurt runs until the summer of 2029, and it remains unclear exactly how much the German club would demand to sanction a sale, though his importance to the side in recent seasons suggests any fee would not come cheap.
Since arriving in Germany, Larsson has scored ten goals and provided seven assists in 119 competitive appearances for Frankfurt, underlining the consistency that has made him such a sought-after presence in midfield.
Whether either Manchester United or Newcastle move beyond monitoring the situation to a formal approach remains to be seen, but the level of interest from two established Premier League clubs suggests Larsson's future is likely to become one of the more closely watched sagas of the remaining transfer window.
Larsson's versatility across midfield, combined with his composure on the ball and defensive contribution, has made him a key figure for Frankfurt in recent seasons as the club has established itself as a regular presence in European competition.
Losing him would represent a significant blow to their midfield options, but a sale at the right price would also provide the Eintracht board with substantial funds to reinvest elsewhere in the squad as they continue building on recent progress under their current sporting structure.