Conway was hurt during the first half following a tackle by Jonathan Hogg and was taken to hospital for X-rays on the injury.

Mackay is waiting to learn the extent of the damage and was left baffled as to why the referee failed to send off Hogg for the challenge.

"We have sent him for an X-ray and we hope he has not broken his ankle," said Mackay.

"I thought it was an appalling and horrendous challenge. It was a scissors tackle. I can't understand the referee's decision on it. It was a sending-off for me.

"I'm disappointed for Craig because he started the game really well. He was having a good go at Carl Dickinson and was looking good."

The 26-year-old was making his first start since 11th February against Watford and has made 37 appearances in all competitions for Cardiff since joining the club from Dundee United last summer.