The 28-year-old spent the latter part of last season on loan at Norwich City from MLS outfit Sporting Kansas City.
He returned to America at the end of the season as Norwich did not take up their option on him which was believed to be £2million.
Now, with his option reported to be less than half that, a number of clubs are showing an interest.
Sky sources understand that Crystal Palace, Middlesbrough, FC Copenhagen and Rayo Vallecano are amongst the clubs keen on taking him.
Kamara has scored seven goals in 14 appearances since his return to MLS and is keen to make an impact in Europe again.