"Taser has impressed us all with his technical ability during his trial period," development coach Paul Stephenson told the club's official website. "He has good feet and can get himself out of tight areas, has an eye for a pass and has a decent cross on him that can improve further through work.
"He has done well early on in the games he has played for us, but has faded as the minutes have progressed. If we can improve his physical state - his fitness and strength - he will be a good asset to the club and we feel he is worth a chance.
"The ball is now in Taser's court; the hard work starts here and it is up to him to take this opportunity."
Hassan added: "I have been given until the end of the season to try and prove myself, so my aim is to try and get up to the required level of fitness and then work my way into the first team."