The two forwards have often been viewed as fighting for one spot as the Reds' central striker but both played up front during the 3-1 win over Paris Saint-Germain in midweek. Lukaku scored twice, the second following a Rashford shot, before the England international smashed in the dramatic tie-winning late penalty.
After the game in the French capital, the pair conducted their television interview together and the signs are they are working beautifully in tandem.
Of course, both players are also capable of playing in a wider role - something Lukaku did to great effect in the Emirates FA Cup win at Sunday's opponents Arsenal, while Rashford is always able to utilise his pace on the flanks and has appeared there many times.