Borussia Dortmund’s Champions League hat-trick hero Karim Adeyemi has reportedly torn a thigh muscle fibre and will be out of action for three to four weeks. The Bild paper and Kicker sports magazine named the nature of the injury on Thursday but there was no official confirmation from the club yet. Forward Adeyemi sustained the injury early in the second half of Tuesday’s 7-1 triumph over Celtic, after scoring his hat-trick in the first half. He will likely miss at least two matches, on Saturday at Union Berlin, and after the international break on October 18 against St Pauli Hamburg. Adeyemi…