Bradley Orr came on in the first half for Adam Henley after he suffered an injury but he himself had to be replaced 12 minutes later with a suspected broken rib following a challenge with Danny Shittu.
Scott Dann also had to have his head bandaged after being caught by Rob Hulse's elbow in the first half of a feisty clash.
"There were a lot of tackles flying around today and a couple of cheap shots going on out there, which is disappointing," said Appleton.
"Adam looks as if he has done his hamstring again, which is disappointing.
"Brad might have cracked a rib. He is really struggling with his breathing at the minute and is in a lot of pain.
"He is taking a lot of pain killers and we will get him scanned and X-rayed as soon as possible."