Riza has been in charge of Cardiff since replacing Erol Bulut on a temporary basis in September before being given a deal until the end of the season in December.
The 45-year-old enjoyed an excellent start to his tenure, winning four of his first seven games.
But the former Watford coach has only picked up four more victories in his next 24 matches.
Riza brushed off the boos on Tuesday, saying it was his job to take such criticism, but also warned his players he would be making changes in their fight to avoid dropping into League One.
