Davis, 24, joined ex-Wolves defender Edwards' men last month but has managed just three substitute appearances since as he looks to build up fitness, while also being blighted by a recent illness.
Edwards said of the powerful striker, who was also a target of Albion: "Whereas we’d normally have him at the training ground working on those fitness aspects and also doing some other general football training, we’ve not been able to do anything.
"The key thing is that we let him get over the illness and then set to work on his fitness. It really is a question of being patient. I’m frustrated, Keinan is frustrated but nobody can help being ill.
“We both want him out on the pitch in a Watford shirt again as soon as possible. Nobody wants that more than me because he is an exceptional player who will be brilliant for us. But I’m not prepared to compromise things now and then risk him being out for longer."