Chelsea boss Mauricio Pochettino admits his squad is lacking Premier League experience.
Pochettino says his players still need to adjust.
"When you analyse the team, starting XI or players who come from the bench," he said. "There's not too much experience of the Premier League. We are talking about Jackson; he came from a different league.
"He needs to understand the rules have changed and where is the limit to talk with the referee. Like this, many other players, or players who play less than one year. We cannot underestimate the Premier League.
"The Premier League, you can arrive here, but it is the toughest league. Sometimes, as a team, we need to be more mature to manage situations, and then sometimes, we make a mistake.
"There are many factors, but these two are principal. You need to learn quickly; if not, you pay for it."
