Yeates missed Sunday's victory over Notts County after injuring his knee in the Boxing Day win at Fleetwood Town, while Davies had to limp off early into the County fixture with a hamstring problem.
Morais suffered a dead leg in the same game but managed to carry on until the end.
Bantams boss Phil Parkinson is hopeful that none of the injuries are too serious but the three players are still doubtful for the journey south at the weekend.
Parkinson is already without the services of Billy Clarke, who injured his knee against Scunthorpe United earlier this month and is expected to be sidelined until roughly the middle of January.
Parkinson said: "We feel with Davo (Andrew Davies) that hopefully the injury isn't too serious. It seems it may only be a slight strain of his hamstring.
"We will continue to assess him as the weekend draws closer though.
"Yeatesy is going to have a scan today (Tuesday).
"Matt (Barrass, Head Physio) feels it is only precautionary but we just wanted to be completely sure that there is nothing sinister going on inside his knee.
"Filipe Morais also has a dead leg and he is going to be a doubt for the weekend."