(Photo by Carl Recine/Getty Images)Manchester United’s attempt to secure a long-term solution at left-back has run into a major obstacle, with Newcastle United privately insisting Lewis Hall will not be sold. The 21-year-old is admired at Old Trafford because he combines energy, progressive passing and the ability to move into midfield, qualities that would suit Michael Carrick’s possession-based approach. ON APPLE & GOOGLE PLAYUnited have already strengthened midfield and added goalkeeping depth during an active window, but left-back remains unresolved. Newcastle United have firm stance on HallAccording to The Athletic, United view Hall as their leading left-back target and believe he could be receptive to an Old Trafford move. Man United face complications to sign HallUnited’s interest makes sense, but the deal currently looks too complicated to dominate the rest of their window.