The Argentinian had previously been linked with a move to West Ham United in the January transfer window, as David Moyes looked to provide support for Michail Antonio in the Hammers attack.
West Ham remain interested in bringing the 23-year-old to the Premier League in the coming weeks, but Tutto Mercato are reporting that Moyes' former side Everton are now rivalling for his signature.
The report outlines how Eddie Howe's Newcastle United also hold an interest ahead of the transfer window, whilst Serie A side Bologna are also monitoring Castellanos' progress as well.
After signing a contract extension in May 2021, Castellanos still has his future tied down with the MLS club until December 2025 as things stand.
The striker made the move to New York for as little as £400,000 in January 2019 having spent the previous six months on loan in the United States from Uruguayan side Montevideo City Torque.
Since the move, Castellanos has gone on to score 53 goals in 128 games across all competitions for Ronny Deila's side, including 11 goals and five assists in 16 appearances so far this season.