The 25-year-old France international has been a fairly regular fixture in the first team at Old Trafford this term, having made 31 appearances in all competitions so far for the Red Devils.
Martial has scored seven goals and made five assists in all competitions for Ole Gunnar Solskjaer’s men but he has only netted twice in his last 10 games.
The forward drew another blank as he played 70 minutes of Manchester United’s 3-1 win over Newcastle United in the Premier League on Sunday evening.
Former England star Shearer believes that the Frenchman needs to start showing more desire to find the net for his club.