The two Yorkshire sides are among the favourites to be promoted to the Championship next season, with the 2022-23 campaign set to begin at the end of the month.
With the new season just over three weeks away, a number of players have yet to resolve their futures after being released.
The Owls have been one side who have made good use of the free agent market in recent seasons.
Wednesday last paid a fee for a player in 2020 while also utilising loans alongside free transfers.
Barnsley have made use of the free agent market already this summer, with Conor McCarthy joining on a three-year deal after his St Mirren contract expired.
We have scoured the market to see the defenders who available on a free transfer after being released by third-tier clubs.
Every available player has then been ranked by their market value, according to transfermarkt.co.uk data. Take a look...
The Owls have been one side who have made good use of the free agent market in recent seasons.
5. Myles Kenlock
The left-back spent the second half of last season on loan at Colchester United before being released by Ipswich Town after first making his debut for the club in 2015. Photo: Getty Images
6. Paul Downing
The centre-back was one of four players released by Portsmouth at the end of last campaign. Photo: Getty Images
7. Brandon Mason
Mason was one of six players released by MK Dons after joining on a short-term deal in March. Photo: Getty Images
8. Reiss Greenidge
The centre-back was one of several players released by Bolton at the end of last campaign. Photo: Getty Images