Spanish and European giants Real Madrid are reportedly interested in securing the services of the Belgium international goalkeeper in the summer of 2018.
The Sun has claimed that defending Premier League champions Chelsea, who have progressed to the knockout stages of the Champions League this season, are interested in signing Hart as a potential replacement for Courtois.
The England international joined West Ham on a season-long loan deal from City in the summer of 2017 after spending the 2016-17 campaign on loan at Italian club Torino.
The 30-year-old started the season as West Ham’s first-choice goalkeeper, but the former Shrewsbury Town star has lost his place to Adrian and is struggling for playing time at the moment.
Hart has featured in 14 Premier League matches for West Ham so far this season, playing a total of 1260 minutes of league football, according to WhoScored.