Scouting interest predates his first league start
Barcelona's scouts began tracking Arnolin during his appearances for Portugal's Under-18 team and have continued watching him at Under-19 level, Goal.com reports. According to Tribuna.com, João Amaral, who leads Barcelona's scouting operation in Portugal, has been following his progress.
Arnolin is not the first defender Barcelona have pursued this year. Goal.com reports that the club sought to sign Twente's Dutch defender Ruud Nistad in the summer of 2026, but Twente would not discuss a departure despite interest from Barcelona and Premier League clubs.
A midfield assignment against Porto
Arnolin's first senior league start for Estoril came on October 31, 2026, against Porto at the Estádio do Dragão. He played in defensive midfield instead of his usual center-back position and left the match in the 62nd minute, when Estoril were two goals behind. Porto went on to win the Primeira Liga game 4-0.
During his time on the field, Arnolin completed 13 of 15 passes and had 26 touches, along with three tackles and six clearances, according to Goal.com. He had made four other Primeira Liga appearances before earning that first start.
The 1.83-meter-tall defender has a contract with Estoril through June 30, 2029. His father, former player Grégory Arnolin, also played in Portugal, with Marítimo and Gil Vicente among his clubs.
