Former England manager Sam Allardyce has admitted that he is surprised that Manchester United did not sign a “proven” talent in the summer transfer window. Manchester United reinforced significantly in the summer for Red Devils former manager Erik ten Hag, who was sacked by the Premier League club last week. French defender Leny Yoro and Netherlands striker Joshua Zirkzee arrived at Old Trafford from Lille and Bologna respectively in July. Erik ten Hag was also reunited with two former Ajax players in the summer, with United signing Matthijs de Ligt and Noussair Mazraoui from Bayern Munich. Un…