The Phillies placed Knapp on the paternity list Thursday.
Philadelphia summoned Rafael Marchan from Double-A Reading in a corresponding move, and he'll presumably start at catcher in one half of Thursday's doubleheader with the Nationals. Since J.T. Realmuto returned from the injured list in late May, playing time has been predictably scarce for Knapp, who has made only eight starts over the past two months.
