Rangers are set to see David Bates leave Ibrox this summer.
Leeds United's defence frailties were exposed once again on Friday night, so adding to their options this summer is a must.
Celtic need another centre-back before the end of the transfer window.
Barnsley beat Championship and Yorkshire rivals Leeds United to the signature of Liam Lindsay, who is already being linked with Premier League clubs.
Barnsley pulled off an inspired deal to sign Liam Lindsay from Partick Thistle but the defender is already attracting Premier League interest.
The Barnsley centre-back's dad played as a goalkeeper in Celtic's youth team.
Barnsley held Sheffield Wednesday to a 1-1 draw at Hillsborough in October.
Leeds United were linked with Liam Lindsay back in January, but he would ultimately move to their Championship rivals.
The defender was heavily linked with Leeds United prior to his switch to Barnsley.
Liam Lindsay's breakthrough season with Partick Thistle appears to have earned him a move to Barnsley rather than Rangers.