Manchester United defender Luke Shaw could not complete the first half against Luton and had to be substituted. Luke Shaw had to be substituted a week ago at half-time against Aston Villa after suffering an injury. Shaw did not train all week and Erik ten Hag expressed doubts over whether he would make the game against Luton. But nonetheless, Shaw did start against Luton. He was booked midway through the first half, and he was substituted just before half-time, heading straight down the tunnel. Another Luke Shaw injuryLuke Shaw has already had two spells out with injury this season. Last week,…