Andrew Halliday has admitted tempers came to the fore after Middlesbrough's 2-0 defeat at Barnsley.
Gordon Strachan's side continue to defy their pre-season promotion favourites tag despite a string of high-profile signings and have so far collected just four points from as many games.
But Halliday insists the team are determined to bounce back from their disappointing start after the international break.
He told the club's official website: "There were a few arguments, it shows how much the defeat hurt. It also shows the team spirit we've got.
"All these new players have come in but there are no cliques. Everybody was disappointed. Everybody was asking themselves for more.
"I hope the fans realise how much everybody was dejected in the dressing room after the game.
"For an hour after the game we were still discussing what went right and what went wrong and trying to take it all in."