One of the big criticisms that came the way of Manchester United boss Erik ten Hag last season was his apparent reluctance to rotate his squad. Even against fourth-tier Newport County in the FA Cup third round, for instance, the Dutchman handed starts to Lisandro Martinez, Andre Onana, Diogo Dalot, Raphael Varane and Bruno Fernandes. Did an over-reliance on a few key players play a role in the injury issues Manchester United suffered during a campaign of relentless fitness concerns? That was one concern. Others, meanwhile, felt that Erik ten Hag should have been quicker to hand opportunities t…