Reece James appeared to applaud Mason Mount during Chelsea's dramatic 4-3 win over Manchester United on Thursday.
Mount made his first return to Stamford Bridge since leaving his boyhood club to join United last summer in a £60million move.
His introduction in the second-half was greeted with jeers and boos, with some Blues supporters appearing to believe Mount was something of a 'traitor'.
However, Reece James looked to have clapped for his former team-mate as he made his way onto the pitch.
The Blues captain was sat behind the bench as he continues his recovery from a long layoff after suffering a hamstring injury.