The issue with yellow cards pre-dates Maresca’s appointment in June.

Former Chelsea manager Mauricio Pochettino spoke last season about how “silly” bookings were a problem and showed video clips to his players to try to rectify the issue.

The Blues were punished last season for not adapting to new Premier League rules for dissent.

Jackson picked up 10 bookings last season but only one was for a foul, the others were for dissent, not retreating quickly enough for a free-kick and entering the field of play when a substitute.

Other players fell foul in similar situations and captain Reece James received two red cards – including one for two yellows – despite playing just 421 minutes.

The immaturity of Chelsea’s young squad may be another factor and with centre-back Thiago Silva having departed in the summer the average age of the group has dropped further to 23.4, according to data from Transfermarkt.

The Blues also have the lowest average height in the league, according to Transfermarkt, averaging just over 5ft 8in, which was another issue Pochettino complained about when in charge.

It perhaps leads to a tendency for players to look at other ways to try and impart their physicality on matches.

And under both Pochettino and Maresca Chelsea are firmly a possession-based team, trying to implement various pressing styles. That pressing can lead to bookings in transition phases and there is a tendency for teams operating these tactics to produce tactical fouls to stop counter-attacks.

Professional Game Match Officials Limited (PGMOL), the body which governs referees in England, has also changed the rules in recent years, with an automatic yellow card now expected to be brandished in several situations.