A source with knowledge of the situation told ESPN that the initial fee is US$1.45 million with add-ons pushing the total fee to as high as $3.75m. Another source added that Bello would prefer to move to Bundesliga side Arminia Bielefeld, but the German club's offer -- $670,000 according to The Athletic -- is well below Atlanta's valuation.
Bello, 20, is keen to depart for a European club, and Atlanta want to cash in given that the player's contract expires after the 2022 MLS season. Bello could sign a pre-contract as early as this June.
Bello, a product of Atlanta's academy, has seen his playing time steadily increase since making his professional debut in 2018. He has made 53 league and playoff appearances with the Five Stripes, scoring three goals and adding four assists.
The Atlanta left-back has begun making inroads at international level, making six appearances for the United States, including two World Cup qualifiers.