The NSW Blues representative duo both sustained their respective ailments in the narrow 26-24 loss to the Brisbane Broncos at Suncorp Stadium, Brisbane on Sunday.
Dragons High Performance Manager Andrew Gray indicated both players could face extended periods on the sideline but the full extent of the injuries will not be known until the result of the scans.
"Josh Dugan looks like he's broken his thumb which we'll need to confirm with an x-ray," said Gray.
"Josh did this early in the second half so he did extraordinarily well to stay out there and play on with this injury for the remainder of the game, as it was very painful.
"It's difficult to put a time frame on the length of time he could potentially miss until we get the results of the x-ray.
"We can then determine the exact extent and position of the fracture but it could be up around four to six weeks.
"Trent had a twisting injury to his knee late in the game and we brought him straight from the field.
"At first glance it looks like he has sustained a medial ligament injury and when this occurs it can do other things to your knee.
"He we will need to see the results of the MRI to get a firm diagnosis before we know exactly how long he will be out for."
Article with thanks to the St George Illawarra Dragons - Dragons.com.au.Follow @NRL_Dragons on Twitter