The French defender returns to Hillsborough on a permanent basis.
Sasso (second right) reacts to Wednesday's play-off final defeat
Sasso spent the 2015-16 campaign on loan at Hillsborough but returned to parent club SC Braga earlier this summer.
Though there was little talk of a return for the Frenchman throughout pre-season, speculation resurfaced after the Owls suffered a defensive crisis in Tuesday's 3-1 defeat to Burton Albion.
Already without captain Glenn Loovens at the Pirelli Stadium, Wednesday lost Tom Lees ahead of kick-off and emergency centre-back Jose Semedo shortly before half time.
Wednesday haven't conceded in either of Lees' games this season (right)
That saw head coach Carlos Carvalhal forced to deploy left-back Daniel Pudil in an unfamiliar central role; however, it is a problem that should be avoided in future now Sasso has returned.
After signing a one-year deal on Friday, the 25-year-old, for whom the Owls have paid an undisclosed fee, posted on Twitter: "Finally back home! Glad to be part of this family once again."
Sasso could make his second debut in Saturday's Championship fixture against Leeds United, though Lees is expected to return against his former club.
Nevertheless, Sasso added: "For the time being, let's win the derby tomorrow."
Finally back home! Glad to be part of this family once again. For the time being, let's win the derby tomorrow. #swfc— Vincent Sasso (@vincesasso) 19 August 2016
Carvalhal issued his own Twitter message ahead of the game, posting a picture of the Wednesday supporters alongside the caption: "We are one. Let's show the power of Hillsborough tomorrow..."
We are one— carlos carvalhal (@carloscarvalha2) 19 August 2016
Lets show the power of Hillsborough tomorrow... pic.twitter.com/7Zqs0b7qA0