The Armenian midfielder Henrik Mkitaryan , who has now gone and joined up with Arsenal in the summer transfer window. He will now wear the Jersey Number 7, seven , which was formerly worn by the Chilean striker Alexis Sanchez, in the E.P.L. number 777, seventy seven in the Europa League. But U.E.F.A have told arsenal that according to the football rules , no footballer can wear a jersey with the number which was worn by another player during the tournaments . For example Alexis Sanchez had worn the jersey number 7 , seven during the Europa League matches. So Henrik Mkitaryan will wear jersey number 77, seventy seven. And the Gabon striker Pierre Emirick Abumayang will not be allowed to play any match in the Europa League. The reason being in the Champion League this year with Borussia Dortmund, and the German club Borussia Dortmund failed to progress into the group of 16, sixteen a, and they too will be playing in the Europa League this year. He can not play for two clubs in two major tournaments in a single year.