Rangers need defensive cover following the sale of Jean Alain Boumsong to Newcastle United a couple of weeks ago and Alex McLeish is said to have made enquiries for Hierro.
The 36-year old joined seven of his team mates on the transfer list last week as Bolton look to raise cash to do some business in the January transfer window.
Hierro only joined Wanderers in the summer after having a spell in the Far East with Al-Rayyan. He has made 16 appearances during his time in Lancashire, scoring one goal in the defeat against Norwich City in December.
Wanderers manager Sam Allardyce has distanced himself from the reports and says that Rangers have not yet made an approach for the players services.
"We haven't heard anything from Rangers." he said