Mame Biram Diouf has resumed training after missing a number of sessions with Bundesliga outfit Hannover.
The former Manchester United striker is believed to be at loggerheads with the club, who want him to extend his contract that is due to expire in the summer.
However, the 26-year-old is said to have no intention of agreeing to fresh terms and would ideally like a transfer this month.
That has alerted new Cardiff City manager Ole Gunnar Solskjaer, as well as Stoke City boss Mark Hughes, according to Sky Sports News.
Diouf has scored five goals in 12 outings this season.