Cagliari had been linked with free agent Yerry Mina, but Sky Sport Italia claim Fiorentina have suddenly surged in front and are close to an agreement.
The Colombia international defender turns 29 next month and is out of contract after five years at Everton.
He was said to be on the verge of signing a new deal with Claudio Ranieri’s Cagliari, who were promoted via the play-offs this summer.
However, now Sky Sport Italia insist Fiorentina have jumped in front and put a larger salary offer on the table.
They can also promise Europa Conference League football, as they qualified thanks to the exclusion of Juventus for financial irregularities.
Mina isn’t the only defender targeted by the Viola, who are still in the hunt for Josip Sutalo of Dinamo Zagreb.
His current club wants to wait until after the results of the Champions League preliminary round before deciding on his future.
Talks also continue with FC Copenhagen for goalkeeper Kamil Grabara.