Alan Shearer stated that Manchester United need to make four signings to be competitive in the biggest tournaments again.United secured their spot in the FA Cup semi-finals courtesy of a 2-1 victory over Norwich City at Carrow Road on Saturday, with Odion Ighalo and Harry Maguire scoring the goals.Although the win stretched United's unbeaten streak to 14 games in all competitions Shearer believes several additions are required at Old Trafford in the summer.“I think three or four big players, a