By Tom Victor Manchester United wonderkid Shea Lacey has signed his first professional contract with the club this week, after celebrating his 17th birthday over the weekend. The teenager, dubbed the Scouse Lionel Messi, has yet to make his senior debut for United. However, after some impressive form at under-18 level, he was invited by Erik ten Hag to join first-team training this month. United have a rich history of welcoming academy graduates into the first team. Just this season, teenagers Kobbie Mainoo and Alejandro Garnacho have earned significant game time, while 19-year-olds WIlly Kamb…