Dimitar Berbatov explained his concern for Manchester United this season.
United sit in eighth in the Premier League and they have seen some of their most high-profile forwards, such as Jadon Sancho, Antony, Marcus Rashford and Rasmus Hojlund struggle for various reasons.
Sancho has now left for Borussia Dortmund on loan but there is speculation that another forward could join in the January transfer window.
The need for reinforcements was highlighted as United beat Wigan in the FA Cup on Monday, but failed to convert some relatively straightforward chances.
Former United striker Berbatov is worried by the profligacy on show.
He told Betfair: “They created a lot of chances against Wigan, they didn't take as many as they should have. I'm worried. There is enough proof from this season so far that if you don't take your chance then you will suffer. Everyone knows that.
“In the case of United, there needs to be more goals. It's a good win, but it shouldn't give them false confidence that they are ready to go against Tottenham. No, it's a completely different game. Everyone needs to be on their toes against Tottenham, completely concentrated and ready to fight for the three points.”