Roma have also been monitoring his situation as are a number of Premier League clubs. Johnson joined Liverpool for £18m which made him, at the time, the Reds' most expensive ever defender.
Manchester City will not give up in their pursuit of Liverpool forward Raheem Sterling this summer.
City chairman Khaldoon Al-Mubarak has vowed to spend whatever it takes to win the Premier League and Champions League next season with Sterling their top target to make it happen.
City’s need for homegrown players has been accentuated by the departures of James Milner, Scott Sinclair and Dedryck Boyata already this summer, and they could be forced into paying over the odds for Sterling, who was rated as the sixth most valuable player in the world in a report published earlier this week.
Finally, Liverpool are set to sign Bolton goalkeeper Adam Bogdan.
Bogdan will become a free agent when his contract expires next month and has received a host of offers from various clubs.
But the Guardian believe that he will join the Reds and that Rodgers sees him as ideal competition for Simon Mignolet.
Mignolet finished the season strongly despite suffering a loss of form mid-way through the campaign.
While Liverpool had been looking at more experienced and more expensive keepers, Bodgan is seen as a sound shotstopper and a bargain at that.