The Telegraph reports relations between David Luiz and Frank Lampard have deteriorated with the defender becoming a disruptive influence.
Luiz was told to train away from the first-team squad ahead of the opener with Manchester United and will now complete a surprise switch to Arsenal.
Luiz and Lampard were involved in a bust-up way back in 2013 during their respective first spells at the club.
Chelsea were beaten 3-2 by Rubin Kazan in the Europa League, with Lampard clashing with his teammate over his defensive responsibilities.
Lampard was seen jabbing his finger into Luiz’s chest, with the pair clashing as they made their way off the pitch.
Yossi Benayoun was even forced to act as peace maker with boss Rafa Benitez publicly discussing the incident.
Luiz spent another season at Stamford Bridge before joining PSG for a world-record £50m fee, with Lampard also leaving the club in the summer of 2014.