Clubs in Saudi Arabia have pursued an aggressive recruitment strategy in recent months and have set their sights on Liverpool's midfield trio.
Sources have told ESPN that former Liverpool captain Steven Gerrard, who was recently appointed manager of Al Ettifaq, is keen to bring Henderson to the club.
Al Ittihad are interested in signing Brazil international Fabinho, but sources told ESPN that Liverpool have not received any formal offers for their players.
The trio could join former club teammate Roberto Firmino in Saudi Arabia after he signed a three-deal with Al Ahli after his departure from Liverpool.
Henderson has two more years left on his contract at Anfield with Fabinho's deal ending in 2026. Thiago becomes a free agent at the end of next season.
Both players could see their playing time limited next season with Liverpool signing Dominik Szoboszlai and Alexis Mac Allister, while Trent Alexander-Arnold excelled in midfield in the latter stages of the previous campaign.
Liverpool kickoff their preseason campaign against Karlsruher in Germany on Saturday.