Advice with husband's injury

Hello! I'm not sure if this would be strange or appropriate here but my husband had had an accident on his sub and ended up tearing his ACL, RCL and his meniscus. He ended up getting sent home early from his deployment because he couldn't really respond to anything that might happen on the sub (casualty or emergency for example.) His boat doc honestly thought he was lying about it and just trying to get out of the deployment so it's really bothered him mentally. We're coming up on his surgery date in a few weeks but he's absolutely itching to get back on the sub because he feels like he's failing everyone on the boat and they're all pissed at him. I've been trying to help him with his guilt but it doesn't really seem to be getting through to him. Do you guys happen to have any advice on how I can help him better or anything along those lines? Thanks for any help!