Pochettino's men travel to Old Trafford later today but, despite boasting the best defensive record in the Premier League, the Argentine coach says that the Saints must be prepared to face a player on a par with two of the world's finest.
"I was speaking about it with my staff and we were saying he is the type of football player who is able to understand what is needed and what's required of him at every single phase of the game," the 41-year-old told reporters.
"I honestly rate him as high as Cristiano Ronaldo and Messi. I have a great admiration for how he is as a football player.
"I think he's an amazingly talented football player and I rate him as high as those two players."
This afternoon's game is scheduled to kick off at 3pm.