Ralph Hasenhuttl's may have to approach the 40-year-old after injuries to their main keeper Alex McCarthy and backup Fraser Forster.
McCarthy picked up what appeared to be a hamstring injury in Southampton's 1-1 draw against Brighton and could be out of action for a few weeks as a result.
In addition to second choice keeper Forster being out injured, Hassenhuttl only has Harry Lewis as a recognised keeper to chose from ahead of their next match against Arsenal.
With that in mind, talkSPORT's Alex Crook has reported that a move for Caballero could be on the cards.
The 40-year-old veteran is a free agent since leaving Chelsea at the end of last season after rejecting a new contract from the club.
The Argentine's prospective move to the south coast looks even more likely after Hassenhuttl criticised McCarthy for staying on the pitch when he was nursing the injury.
"Alex must be definitely more professional than that," the Saints boss said.
"If you have a goalkeeper that is not 100% fit in that moment and cannot jump and then you send someone back into the line, then the rebound that comes out is normally offside."