Against Forest, Rashford scored United's first goal after sweeping in a well-worked corner routine initiated by Christian Eriksen and then teed up Anthony Martial to fire in the second midway through the first half.

With Martial operating as the main striker, the England international played a little deeper on the left, which enabled him to cause problems for the Forest defence with his movement.

"I think Marcus enjoys it more, he looks better certainly, in the position we saw tonight," Shearer said on Amazon Prime.

"He's been given a little bit of freedom - if he wants to go down the middle at times, he can.

"But when he's got all that space to run into from out wide, he's a better player in doing that and he's very, very good at doing that.

"In terms of him being a centre-forward, he lacks that killer instinct, that natural ability to think 'yeah, I'm going to get in there, I'm going to get the two or three yarders'.

"But there's no doubting his ability, he's a fantastic player."

Owen, also working at Old Trafford as a television pundit, agreed with his former England strike partner.

"I do feel that Rashford is better on the left, he will contribute a decent number of goals each year," said the former Liverpool and Real Madrid forward.

"But he's not going to be the Ruud van Nistelrooy, the Robin van Persie, the Wayne Rooney who scores 30-plus goals a season.

"Obviously he is a huge asset to this football club, gives them something different, gives them pace, gives them directness."

United's need for a new 'out and out' striker has long been apparent and the search has been accelerated by Cristiano Ronaldo's departure by mutual consent before the World Cup.

Frenchman Martial, 27, staked his claim to be manager Erik ten Hag's regular striker with a decent showing against Forest, but there remains the feeling he has already had enough chances to prove his worth to United over eight seasons without ever being fully convincing.

PSV Eindhoven's Cody Gakpo was a long-time attacking target - even though the Dutchman, like Rashford, is seen as being more productive behind a frontman - but United appear to have been beaten to his signing by Liverpool.

After beating Forest, Ten Hag admitted it would be "good" to get another forward but only if United's "sporting and financial criteria" were met.

"I'd certainly look to go into the market to see if they could find a centre-forward," added Shearer.

"But that's easier said than done as that many clubs are looking for that guy that can go out and get you 25 goals a season."

Owen, who also had a spell at Old Trafford, added: "Rashford should be getting 20 a season if you include all the cups. In terms of the league, if he gets 15 that would be a very good return.

"But I think Manchester United need that number nine - whether it's Martial or another player."

Rashford suffered a dip in form under United interim boss Ralf Rangnick last season, scoring just twice in 23 appearances and rarely playing a full 90 minutes.

This season, looking reinvigorated under Ten Hag and playing with a smile again, he has netted 10 times in 21 games for his club.

"I don't know if it is as good as I've ever been playing but I'm definitely enjoying it," Rashford told Amazon Prime.

"We're winning a lot more football games and our level has been a lot higher. I'm happy with how were developing and hope we can keep kicking on.

"It's a completely different mindset to last season, a different team playing different football.

"For me, when you're not in the team and coming on, there is a different mindset and you have to think about making an impact and you're not sure when you get another chance or another goal.

"But I'm enjoying what I'm doing at the minute."