If Shaul has had a contract offer on the table from the club then why hasn't he signed it? If he had then no problem, if the club hadn't actually put an official offer in writing but agreed verbally and in principle then I can see why they'd honour this.
However if they had and he hadn't signed it because he felt the deal wasn't good enough etc then that's just unfortunate on his part and the club would be under no obligation to stand by the offer.
Just because its sport it makes no difference, I once had a contract offered on a job that I wasn't sure of and didnt sign it then my circumstances changed due to illness which meant I then lost out on the contract. I had no complaints as I hadn't signed when I should have to secure my future, thats just life.