Manchester United’s under-powered attack, Brentford’s £39m bargain and Dewsbury-Hall delivers for Everton Arsenal’s treatment of Gabriel Martinelli has been questioned by Ian Wright after the Brazil forward was left out of their squad for Friday’s opening game against Coventry. Martinelli turned down a move to Galatasaray last week after Arsenal had agreed a fee with the Turkish club and the former striker Wright revealed on Sky Sports after the Coventry game that no one at the club has spoken…