Gary Neville has picked out three factors that will make it difficult for Thiago Silva to adapt to the Premier League.
Silva was snapped up on a free transfer from Paris Saint-Germain this summer, after the Brazilian had led the Ligue 1 giants to the Champions League final.
The soon-to-be 36-year-old has been brought in to add some vital experience to a fragile Chelsea defence.
But Neville has warned Silva it may take time to adapt to the intensity, the number of games and the speed of football.
“Again, it’s an unknown. 35 [years old], 36 next week, played in the French league now for a number of years,” Neville said on MNF on Sky Sports.
“The intensity in the French league is nothing like our league. That’s not to say Paris Saint-Germain are not a great team, they just got to the Champions League final, but you’re talking about the Premier League.
“Particularly the intensity of this Premier League season, it’s compact.
“It’ll be a massive challenge for him in terms of the amount of games, the speed of football compared to what he’s been used to. It’ll be a step up in that respect.
“Can he play in matches, can he play at this level? Of course he can, he’s a world class player.
“But at this stage in his career… again when you ask if Chelsea can win the league, it’s just a complete unknown. Will he adapt?
“What’s the goalkeeper going to be like? How the forwards are going to adapt?
“There’s a lot of unknowns with Chelsea. But on the other side of that, massive excitement.
“I’m intrigued to see how this world class defender who’s played many years for Brazil, been a wonderful player for Paris Saint-Germain, is going to do in our league.”