Anthony Martial is the most expensive teenager, joining United from Monaco for a deal set to rise to Ã‚Â£58.7 million.
The Frenchman is touted as the next Henry. And Henry believes United has undertaken a massive gamble in acquiring the 19-year-old.
With the young striker still developing, Henry believes Martial will need time to develop.
Ã¢â‚¬Å“He has pace, can he score a a lot of goals? I actually donÃ¢â‚¬â„¢t know because heÃ¢â‚¬â„¢s only played 52 games. ItÃ¢â‚¬â„¢s a weird one for me to say. ItÃ¢â‚¬â„¢s a massive gamble that you need to take nowadays because of the situation Man United have,Ã¢â‚¬Â Henry told Sky Sports.
Ã¢â‚¬Å“We saw him at the Emirates last season playing with Monaco and causing trouble to the Arsenal defence, he has a bright future. But thereÃ¢â‚¬â„¢s always a question mark, whether he can perform.
Ã¢â‚¬Å“We saw it last season with [Angel] Di Maria, an established, experienced player who couldnÃ¢â‚¬â„¢t make it through the ranks at United.
Ã¢â‚¬Å“He played at the weekend against PSG and he can play in the middle. Is it going to take him a bit of time to adjust and understand what the job requires? Yes, because he only played 52 professional games. It [the fee] is mind-blowing.
Ã¢â‚¬Å“You have a lot of boxes that you canÃ¢â‚¬â„¢t tick with him because I repeat he has only played 52 games. You are not the same player you are after 100 or 150 games from the 50 that you start with Ã¢â‚¬â€œ especially as a centre-forward, you need games, experience and time out there to perform.
Ã¢â‚¬Å“I wish him all the best and think he can do well.Ã¢â‚¬Â