Manchester United will battle Manchester City for the signing of Arsenal forward Alexis Sanchez who can leave on a free next summer, according to reports. Sanchez, the Chilean forward, looked set to join Pep Guardiola's City on the final day of the transfer window in August, after a reported £80 million (about $108 million) bid. Trending: NBA: Has Kevin Durant Worn Out His Welcome at Golden State in Just One (Championship) Season?