Charlie McAvoy is back. The Boston Bruins rookie defenseman has been out since undergoing a procedure Jan. 22 to treat an abnormal heart rhythm. But the Calder Trophy candidate will be in the lineup for Saturday’s game between the Bruins and the Toronto Maple Leafs, according to B’s head coach Bruce Cassidy. With McAvoy back, and Kevan Miller, Noel Acciari and Brad Marchand still out, Boston fans should expect these lines for Saturday’s game at TD Garden: