The England international latched on to Bruno Fernandes’s pinpoint through ball and fired past Robert Sanchez on 62 minutes, to draw United level after Danny Welbeck’s first-half opener.
The Reds would go on to win the game, through Mason Greenwood’s header, but Rashford was not on the pitch to see it having been replaced by Daniel James.
And after the match, the manager shed some light on why Marcus had to make way.
United take on Granada in the first leg of the Europa League quarter-finals on Thursday, with another big Premier League match – away at Tottenham Hotspur – arriving three days later.