Italy striker Pablo Osvaldo completed a loan move to Juventus on Friday after a troubled spell in England, while Napoli signed defender Faouzi Ghoulam from Saint-Etienne on a quiet transfer deadline day in Italy.
"I'm very happy," Osvaldo said of his return to Serie A. "Everything happened very fast and I still can't believe it ... It's been a hectic three or four days."
Juventus has the option to buy the 28-year-old before May 31, for 19 million euros ($A29.5 million).
Osvaldo joined Southampton from Roma in August for a club-record 15.1 million euros ($A23.5 million).
The forward scored four times for the Premier League club but was suspended for two weeks on January 23 following a training-ground incident.
Osvaldo was kicked out of the Confederations Cup squad last year for insulting his club coach at Roma in a breach of national team coach Cesare Prandelli's code of ethics.
Juventus is on course for a third straight league title and is six points clear of Osvaldo's former club Roma - its closest challenger.
Another player also returned to Serie A on loan from the Premier League, with former Lazio defender Modibo Diakite signing for Fiorentina from Sunderland.
Earlier, Ghoulam put pen to paper on a four and a half year deal, tying him to Napoli until 2018.
The 22-year-old Algeria international, who played for France at Under 21 level, made 87 league appearances in four seasons at Saint-Etienne.
Ghoulam is Napoli's third signing this month, following the arrivals of Jorginho and Henrique.
Napoli also confirmed it allowed Pablo Armero to join Premier League club West Ham on loan until the end of the season.
Elsewhere, Roma signed Rafael Toloi from Sao Paulo on loan until the end of the season. Roma has paid the Brazilian club 500,000 euros ($A777,000) for the loan and will pay a further 5.5 million euros ($A8.5 million) if it decides to buy the defender in the summer.
Roma also announced Marquinho has moved on loan to Hellas Verona.
Several other deals are expected to be completed before the transfer window shuts on Friday night, with Lazio's Hernanes having a medical at Inter Milan.