Marcus Rashford hopes to fill void left by Zlatan Ibrahimovic, Wayne Rooney

HOUSTON -- Marcus Rashford says it is up to him to fill the void left by Zlatan Ibrahimovic and Wayne Rooney at Manchester United.

Rashford and new £75 million signing Romelu Lukaku will be charged with scoring the goals to fire a Premier League title challenge next season after Ibrahimovic and Rooney left the club this summer.

The England international insists he learned a lot from both Rooney and Ibrahimovic but accepts the responsibility in front of goal will now fall on him.

He told a news conference on Wednesday: "It is obviously going to be different but there was a time when they weren't the people they were. We have to change and develop to become what they were.

"Wayne just let me get on with it. He was always there to give me advice if I needed some. Losing that type of character is difficult but it is football, we have to move on.

"There was a lot to learn from Ibra, not only from the football side of things but just his mentality and the way he trains, the way he prepares for the games. That's what I took.

"It's difficult -- we have different playing styles. To take a lot from his game is difficult. You've got to look outside of just football and take from his personality and what makes him great."

After scoring eight goals in 18 games during his breakthrough season under Louis van Gaal, Rashford was restricted to 11 in 53 last term.

His goal scoring was hampered by Mourinho's decision to play the 19-year-old out wide, but Rashford says it was still a successful season.

He added: "I think the performances last year, the stats are what brings it down. They are the things you want to try to bring up, but they are not the things I was concentrating solely on last season.

"Season by season I have different aims and responsibilities to the team. This year hopefully I will take more responsibility on. That is the aim."