The attacking midfielder has had limited opportunities at St. Andrews this season, but Redfearn admits that trying to sign Shinnie is proving a complicated process.
"It's still ongoing. He's somebody we fancy. These things take time," he said.
"We've got to be patient. We were hoping it would get done before Saturday, but we're not at that stage yet.
"Other clubs are involved. It's not just ourselves in the transaction. Players have got to come and go from a few clubs.
"He's an attacking midfielder with flair and an eye for goals. He would add real competition for places.
"Our interest in the transfer market has raised the performances of our players. They want to stay in."
Shinnie has a vast amount of Championship experience, but he has fallen down the pecking order at Gary Rowett’s side.
The 26-year-old has made just five league starts to date this campaign, with Jon Toral jumping ahead of him in Rowett’s selection plans.
With Diego Fabbrini also likely to move to Birmingham in the near future, according to the Daily Mirror, Shinnie’s chances of getting regular first team action are looking even more slim.
If Shinnie does move to Redfearn’s side, he will be tasked with helping the side move up the Championship table, from their current position of 21st.