Arbeloa addressed both incidents in his pre-Clásico press conference on Saturday, dismissing those who saw significance in the footage of Mbappé departing the training ground in good spirits on Thursday while his teammates were involved in a training session that led to Fede Valverde being hospitalised.
"For a player to leave the training ground laughing is taking things out of place and out of context. Anyone who interprets that out of context — I'll say it again — is misrepresenting the situation."
On the Sardinia trip, which Mbappé took while injured in the days before Real Madrid's match at Espanyol — a game he was unable to play — Arbeloa was equally firm in his defence while confirming the club had authorised the absence.
"All Madrid fans know what efforts he had to make to come to Real Madrid. He had absolutely everything at his previous club and had to give up a lot of things to be at the club of his dreams. We have all seen him as a child in the Real Madrid tracksuit."
He was also asked whether the trip had tested his authority as manager.
"I feel fully vested with the authority of a Real Madrid coach. In the end, they are respecting the coach in charge — and as a player, that is the most important thing."
Mbappé has been sidelined since April 24 with a left thigh muscle injury. He did not travel with the squad for the Espanyol fixture. He trained individually at Valdebebas for much of this week and medical assessments suggest he is close to fitness, with his availability for Sunday's Clásico at Camp Nou a realistic possibility.
Arbeloa confirmed at the end of the press conference that when asked whether he believes Mourinho is "one of us," his response was simply: "Yes."
Barcelona can win La Liga on Sunday with any result better than a Real Madrid win. They have not clinched the title in front of their opponents at Camp Nou since the competition's current format began.