Manuel Pellegrini is reportedly keen on signing the 26-year-old to bolster his options at centre-back.
Long started five times for United States at the recent Gold Cup but has not yet satisfied the Football Association's requirements for endorsement of a work permit.
Premier League clubs must submit their applications before the transfer window closes on Friday (AEST).
"As our biggest ally, it seems strange that a football player from the US can't automatically get a work visa to play in England," Long said.
"Every kid in the USA dreams of playing in the English Premier League.
"Not many players get the chance, so of course I would like to play there some day."
Multiple Ligue 1 clubs, including Marseille, have been linked with Long, the MLS Defender of the Year for 2018.
"I just signed a new contract, so the decision is up to my club and the other team," he said.
