Arsenal starlet Ethan Nwaneri has put pen to paper on his first professional contract at the club, in a huge boost. Arsenal had to fight off strong interest from elsewhere to convince their teenage prodigy to stay, and he has now signed a deal, which Per Mertesacker has hailed as a huge step in his development. The 17-year-old has been outstanding in the academy sides this season, and was given another chance off the bench as he impressed against West Ham in the Premier League. This was a game which saw him come off the bench, much to the delight of the senior players, and midfielder Declan Ri…