The Belgian, who joined United last summer for £90m, has grown into his role under Mourinho and currently has 24 goals to his name across all competitions at the club.
Despite falling victim to criticism during various stages of the season, Mourinho has repeatedly stood by the forward and praised him for his contributions to the team as a whole.
Having been involved in 11 goals in 11 appearances in 2018, Lukaku is coming into his own at Old Trafford and believes he’s now firmly established himself as a key component within Mourinho's starting XI.
“I think the manager in his mind thinks that I’m like his sergeant on the pitch, and that’s strange for a striker because it’s usually the midfielders,” Lukaku told Sky Sports.
“He has been really good but I think he knows I have that soldier mentality.
“I think the work rate I am delivering to the team is a lot and he knows he can come to me whenever. I will always put the team first ahead of myself and that’s something I told him, I said ‘the team is the most important thing’.”