Barnetta was the hero for Switzerland when he netted two goals in the European Championship qualifier against England back in the summer and has been attracting interest from a number of clubs across Europe.
Aston Villa boss Alex McLeish is keen to strengthen his squad in January and has been strongly linked with a move for the Bayer Leverkusen midfielder.
But he faces stiff competition to sign the 26-year-old as Fiorentina have also been monitoring his progress.
And reports in German sports magazine Kicker are now suggesting that Fortuna Dusseldorf, who play in the second tier in Germany, have also made moves to sign the experienced player and want him on loan until the end of the season.
That means McLeish will have to move fast when the January transfer window re-opens if he wants to win the race to sign Barnetta.