The £75m Belgian striker has been dropped in recent weeks after the impressive form of Rashford under interim boss Ole Gunnar Solskjaer.
Lukaku has been benched for United’s last four league games and is seemingly now only starting in the cup clashes.
United’s second most expensive signing now admits he is fighting for his Old Trafford future with Rashford, Martial and Sanchez.
However, the former Everton star has not fallen out with any of his co-stars, despite their battle for places.
“Yes it is tough and intense – but in a good way. It’s all about the team” he said after the 3-1 win over Arsenal on Friday.
“We try to push each other to make sure we win because we know that we are still not in the greatest position in the league but we all want to be in the top positions.
“We want to win a trophy as well.
“The manager has done a great job so yes, credit to him but to the players as well and the team. Everyone wants to play for the team – it’s the team above everything.”
Lukaku missed two games in December due to compassionate leave, where he watched Rashford and Martial find the back of the net.
He added: “Yes, you have to be patient at the end of the day I had to go away for personal reasons I came back and me and the manager had a good conversation.
“I know it is going to take a lot of steps but you know I am closer than ever to my best and I’m really happy.”
Lukaku also revealed the Solskjaer change that has made a big difference to harmony and understanding in the dressing room.
“I have been in the game ten years and been in a lot of dressing rooms we have to be humble at times – we need a lot of communication and Ole does that well.
“Every manager has his own way of working Mourinho had a good way of working and so does Ole.”