Luca Toni has re-signed for Fiorentina, five years after leaving the club to move to Bayern Munich.
Toni, 35, was available on a free transfer after a spell with Dubai club Al Nasr came to an end.
Siena had also been in the market for the ex-Italy international, but Fiorentina beat them to it and, in a statement on their official website, said: "Fiorentina officially announces the outright purchase of Luca Toni. The striker previously scored 49 goals in 71 appearances."
Toni joined Bayern in 2007 and left in 2010, spending spells with Roma, Genoa and Juventus before moving to Dubai at the start of 2012.
Fiorentina had been searching for a striker to partner Stevan Jovetic. Having missed out on Dimitar Berbatov, Borriello was thought to be their next target, but instead they opted for Toni.
He enjoyed the best season of his career at the Artemio Franchi, scoring 31 goals on his way to the 2006 European Golden Shoe.
Coach Vincenzo Montella also recruited Catania midfielder Cristian Llama on a one-year loan deal before the Italian transfer window closed.