HONG KONG. David Moyes admits he is unsure what his strongest side is and does not know which XI will line up for Manchester United on the opening day of the Premier League season.United go to Swansea on August 17 and new manager Moyes is yet to get to know several of his charges.Javier Hernandez has not yet joined up with United on their pre-season tour of Asia and Australia because of his involvement in the Confederations Cup while injuries have sidelined Nani and Antonio Valencia.Captain Nemanja Vidic has missed the tour with a back problem while Wayne Rooney, who is wanted by Chelsea, flew home with a hamstring problem.And it has made Moyes’ task harder. He is quoted by the Guardian as saying in Hong Kong, where United are preparing to face Kitchee on Monday: "I’m still getting to know my players. I have several players back home who I’ve not met yet because of international duties."I don’t have a starting XI for the Swansea game formulated in my head yet. We still have three games in Europe before the season starts. We’ll look at it then.”Moyes has also been frustrated in his attempts to add to his squad this summer, with Barcelona insisting they will not sell Cesc Fabregas and Thiago Alcantara joining Bayern Munich instead of heading to Old Trafford.