#4 Ashley Young
Ashley Young has been the biggest beneficiary of Valencia's injuries. He had a stable season last year which helped him to get a place in the World cup squad as a left-back. Luke Shaw's emergence has forced the manager to use him at the opposite flank. Ashley Young, too, was in his last year but signed a one-year contract extension just a few months before.
After impressing in a few games early on, his performances have been on a downside. Blatantly, he was the worst player for the Reds against Barcelona in the quarterfinals of Champions League. In the first leg, he attempted 11 crosses from the right flank and completed NONE! He made a single tackle and gave away the ball at a number of times. In the second leg, playing at the left-back spot, Lionel Messi ripped him apart. His indecisiveness and lack of awareness aided Messi to score the first goal. It's quite clear, United need a solid and reliable right-back. Maybe Aaron wan Bisaaka?