By Tom Gott Manchester United manager Erik ten Hag has admitted his concern towards the latest injury picked up by centre-back Lisandro Martinez in Sunday’s 3-0 win over West Ham United. Martinez has already missed most of the season with a foot injury and was making just his tenth appearance of the campaign when he went down with a knee injury shortly after the hour mark on Sunday. He would force himself to continue, only to accept defeat five minutes later and limp off the field. “It doesn’t look good,” Ten Hag said after the game. “It seems bad, we have to wait and make the right diagnosis….