Shearer says Edinson Cavani's age is a concern as he analysed United's attacking force.
Shearer says Erling Haaland and Kylian Mbappe are "top-class" strikers Man Utd need after the goalless Manchester derby.
Alan Shearer believes Manchester United need the likes of Erling Haaland and Paris Saint-Germain's Kylian Mbappe if they are to improve their goalscoring form in the future.
The former England frontman labelled Borussia Dortmund's Haaland and Mbappe as two "top-class" strikers the Red Devils should be looking to sign following the goalless draw with Manchester City at Old Trafford.
It’s clear United lack the killer instinct in front of goal against the so-called Premier League big six clubs after registering one goal against Tottenham, Chelsea, Arsenal, and Manchester City.
All in all, Shearer does not think United's duo Mason Greenwood and Marcus Rashford are good enough to convert chances created by Portugal midfield maestro Bruno Fernandes, adding that Edinson Cavani's age is a concern.
"Cavani, they’ve got him. He’s 34 in February," Shearer, the Premier League's record goalscorer, told BBC Match of the Day.
"Greenwood maybe that man in two or three years time because he’s got fantastic potential.
"But I think they need a top-class centre forward in this team.
"Greenwood and Rashford should be in and around that six-yard box, there’s no one there, no one at all, nothing on for Bruno.
"He needs more options, he needs a forward in there who will put the ball in the back of the net.
"They’ve got to get in there more often. It was far, far too easy an afternoon for [John] Stones and for [Ruben] Dias. That’s what I think they’re lacking and it showed today."
When asked who United should sign to help them upfront, Shearer replied: "Haaland or Mbappe."