I have had to lay off working out for the last month due to a injury in the shoulder. I have noticed a big loss in my right tricep and chest only. Tried to workout and could not bench press or do one push up. The pain in my shoulder is in the front where the collar bone connects to the shoulder and there is a noticeable not there. What could be the problem with my shoulder and is the muscle loss due to the injury?

The muscle loss is likely because you're no longer working out like you used to on that side. Those that work out regularly gain muscle mass. Unless it's kept up (working out), that muscle mass diminishes.

Obviously you've gone to the doctor about this injury, otherwise I doubt you'd be let off work for it. I would discuss this with your doctor, and don't start working out until the doctor gives the go ahead. You could end up damaging the area even more.

You can build up your muscle again once you're fully healed and the doctor gives you the okay.