England international Rashford endured a miserable 2021-22 season, scoring just five goals and falling out of the team under interim manager Ralf Rangnick.
The 24-year-old has spent his entire career at the Theater of Dreams but was considering a move from United after being dropped for a number of crucial games including the Manchester derby.
Rashford is hoping to revive his career under new manager Ten Hag and Merson insists the coming season will be key in shaping the forward’s career.
“Marcus Rashford needs to show up for Manchester United this season,” Merson told the Daily Star.
“Things have been going smoothly for him until recently, but his confidence is gone and it was difficult for him.
“I’d like to think he’ll be back next season but when he can’t get his confidence back that’s when you start to worry.
“All the work he did off the pitch for a good cause probably took a toll on him mentally as well. But I would expect him to hit back.
“The new manager could suit him. I’m sure Erik ten Hag wants to play a certain way. He wants United to play like Ajax. To quickly push and move the ball.
“But it’s going to be difficult for a team with Cristiano Ronaldo to be a high-intensity pressing team. He’s not going to chase every ball, is he?’
Merson has also set a target for Ten Hag as the former Ajax manager seeks to bring success back to Manchester United, who have now gone five straight seasons without silverware.
The former Gunners star added: “If the manager gets them in the top four I think he’s done a great job. I really do.
“He needs to consolidate and just take them to the Champions League. United fans shouldn’t expect much more.
For more stories like this, visit our sports page.
Follow Metro Sport for the latest news
Facebook, Twitter and Instagram.
https://metro.co.uk/2022/06/18/man-utd-paul-merson-warns-marcus-rashford-sets-erik-ten-hag-target-16850037/ Man Utd: Paul Merson warns Marcus Rashford, targets Erik ten Hag | Soccer