Wales international Declan John is staying in Scotland.
Merthyr Tydfil-born John, 22, has been playing for Rangers on loan from Cardiff City and he has made the deal permanent.
John moved to Scottish Premiership team Rangers last summer and has scored two goals in 12 appearances.
Manager Pedro Caixinha has worked closely with John to develop his skills at left-back and told RangersTV: “Declan is a player who was never coached how to play as a left-back.
“He did it a couple of times with us and he did it extremely well because we are a team that likes to attack and have the full-backs join in. He gives us that.
“We are helping him defend the wide area and understand his relationship with the winger in front of him, the midfielder on his side and also the centre-half from his side.
“He needs to know those relationships and which space he needs to cover when he is defending. He is also able to play as a winger.”
John, a Cardiff regular during their season in the Premier League, is intent on regaining a place in the Wales squad and says: “If I’m playing well it’s certainly going to put me in good stead in terms of getting back into the national team.”
While John is focused on his career in Scotland, Cardiff have two matches in four days over the Christmas period.
They travel to play Bolton Wanderers on Saturday (3pm) before entertaining Fulham at Cardiff City Stadium on Boxing Day (3pm).
Warnock will be without striker Danny Ward and midfield player Aron Gunnarsson for both matches.
Ward has a knee injury and could be out until well into the new year, while Gunnarsson has had ankle surgery and will be missing for three months.
“Gunnar has a bit of floating bone around his ankle,” said Warnock.
“They thought they could steady it around, but I always thought it would be better for him to have the operation, get it out and sorted. He’s going to have the World Cup at the back of his mind isn’t he?”
The losses are a blow for the Bluebirds, who are second in the Championship and four points behind leaders Wolves.
It was thought Ward would be out for a month, but he will now be missing until a lot closer to the end of this season.
Gunnarsson has turned down the offer of a new contract at Cardiff and could leave for nothing when his current deal expires at the end of the season.
Warnock, though, still believes the Icelandic international may stay and says: “He might be here next season. If things go well for us there’s no reason why he’s not here next season.
“From my own point of view in a way, it could be good for me that he’s having an operation because clubs might think twice about buying him in January.”
