The striker has only just returned to the Southampton squad after completing a three-game ban from the Football Association for an incident involving the Newcastle goalkeeping coach during their 1-1 draw in mid-December.
The 28-year-old Italy international has made nine starts for Southampton in the Premier League since his club-record move from Roma during the close-season.
Osvaldo has scored three league goals for Mauricio Pochettino's side and was in contention for Southampton's FA Cup fourth-round tie against Yeovil Town on Saturday before the club's announcement.
A statement on the club's official website read: "Southampton Football Club has suspended striker Dani Osvaldo for two weeks, following an incident at the club's training ground.
"The club has taken swift and proper action for what it considers a breach of the conduct expected of its players.
"Southampton will be making no further comment on this matter."
Osvaldo will miss this weekend's FA Cup tie, plus Premier League matches against leaders Arsenal and Fulham before returning to the squad for the visit of Stoke City.
