Tottenham Hotspur are working on a deal with German side Hertha Berlin to sign their exciting 16-year-old Boris Mamuzah Lum. The German youngster is on the radar of the north London club and it is believed we have already welcomed him to N17 for a visit. But we will face serious competition for the prospect’s signature with some of Germany’s biggest clubs also keen on him. Tottenham working on Boris Mamuzah Lum dealAccording to a report by Bild, Tottenham are making big steps towards securing the services of the promising talent. It is claimed the 16-year-old visited the Tottenham Hotspur Stad…