Ole Gunnar Solskjaer’s men have made their worst-ever start to a Premier League campaign and currently sit 12th with just two wins from their first eight league games.
While United have looked defensively more stable, following the summer arrivals of Harry Maguire and Aaron Wan-Bissaka, they have really struggled going forward and have scored just nine times in the league this season.
And former Red Devils star thinks that even the game’s very best would find life hard if drafted into the side.
“The winter transfer window is difficult and also on the pitch Manchester United aren’t producing as a team at the moment,” Berbatov wrote in his column for Betfair.
“It doesn’t matter how good you are, Lionel Messi or Cristiano Ronaldo could go there and they would have difficulty because the team is not producing as a team.
“When you sell two of your main strikers you need to bring in at least one, just in case. Everybody can see that that Manchester United need a back up, Anthony Martial is injured and there isn’t another really strong proven goalscorer.”
Though adamant playing at Old Trafford will be challenging for any player at the moment, Berbatov has backed the club’s reported pursuit of Juventus striker Mario Mandzukic.
“They have the talent in the young players but at the same time you need someone like Mario Mandzukic,” he wrote.
“I think he is a really good football player and he hasn’t played before in England but I hope if he comes he can straight away get into the rhythm of the Premier League.
“Zlatan Ibrahimovic was 34 when he signed for United and he didn’t have any problems. Mandzukic is a similar age and hope he could have the same impact if he signs.
“I think his age is a good thing; Martial, Rashford and Greenwood are all young players so they need that time and assurance that they don’t need to worry and they can learn from the experience of Mandzukic.”
Aside from needing reinforcements up front, the Red Devils are also lacking in the middle of the park, according to Berbatov.
“I like Nemanja Matic as a player but he in not getting that time on the pitch that he needs, so they are probably not going to depend on him as much as he wants them to, so for me they need to strengthen the midfield,” he continued.
“One or two players, I don’t know, they just need a player that can help them and give them that solidity in deference and creativity going forward.”