Sampdoria have replaced coach Ciro Ferrara with Delio Rossi after a 3-1 loss at Catania, while Serse Cosmi has parted company with Siena.
Former Juventus coach Ferrara took over at Sampdoria in July, succeeding Giuseppe Iachini, who had orchestrated the club's promotion from Serie B to the top flight.
Ferrara leaves with Sampdoria 14th on the Serie A table, three points clear of the relegation zone after managing five wins, three draws and nine defeats in 17 matches played in the 2012/13 campaign.
His replacement, Rossi, left his most recent post as Fiorentina coach with two games of the last season still remaining after allegedly assaulting striker Adem Ljajic.
Elsewhere, former Perugia coach Cosmi departed Siena following their third consecutive defeat, a run of results which has left the team bottom of the table, four points away from safety.
Cosmi makes way for former Chievo and Brescia coach Iachini.
"I promise to bring enthusiasm and work as hard as I can to keep the team in Serie A," he said.
"If I'm here it is because I believe in the strength of these players."