I'm surprised at all of the criticism here. I love Lingard as a character. He might have the maturity of a 10 year old but he seems a great character in the dressing room and epitomises what the club should be about - young players brought through the ranks with a winning mentality engrained in them from a young age.
He might not be good enough to start every game but at the top level it's a squad game. He's no Luke Chadwick. He's a regular England international and an academy player who is good enough to be one of 5 or 6 forwards competing for 3 or 4 positions. He is also a very different type of player than the others. That is a really great asset.
The closeness of that group of young players (Pogba, Lingard, Rashford, Martial, Lukaku) is the recipe for long term success for the club, even more so with the next generation in Gomes, Garner, Greenwood and Chong coming through also. They just need strong leadership and an experienced core of top class players around them to establish that winning culture.