Kevin Blackwell said on the official Leeds website:"He will go for a scan on Monday and the reason we have had to delay it for four days is because we have to let the swelling go down first.
"Through experience with Dominic Matteo we know that when it is x-rayed straight away the swelling can hide the extent of the damage. That put Dominic back nearly eight months so we don't want to miss anything now with Richard.
"He's gone for the shot, then Michael Johnson has come across and taken the ball away from his foot, but the power of the strike and hitting Johnson coming the other way has actually opened up the knee.
"We will know the exact extent on Monday but it is not going to be a little knock that's for sure.
"Richard is absolutely distraught at the moment because he's not been injured for five or six years, he comes to Leeds and then three weeks into his career he's done his knee in.
"We are keeping our fingers crossed but the best will still be six to eight weeks."