Primarily a centre back, 6ft 1in Gabriel (full name Gabriel Armando de Abreu) can also play at left back or right back. This season the 24-year-old was an ever present in the Villarreal side that conceded just 17 goals in their first 19 La Liga matches and has gone 18 games unbeaten.
He began his career with Esporte Clube Vitória in Brazil, making his debut aged 19 before going on to feature more than 130 times for the Salvador club.
Arsenal have been granted a work permit for Gabriel and the transfer is subject to the completion of further registration and regulatory processes.
Gabriel said: “I came from a club that is not that big in Brazilian football. I went to Spanish football and that was another dream come true, to play in Europe. A while ago I had a really huge desire to play in the Premier League, so since that point I put it in my head that I really wanted to do it. I had a talk with my family and I told them that it was my dream to play in the Premier League. Getting here to such a big club is so gratifying.
“I am arriving at a big club and the fans can expect to find a Gabriel with a great will to help everyone. Not just thinking of me as an individual, because to me that is not important. I care more about helping the team and my team-mates. I want to help everyone, so the fans can expect a Gabriel that on the field has a lot of will to be able to help the team win important things.”
Costa Rica international Campbell, 22, is joining Villarreal on loan until the end of the season to gain more valuable first-team experience. He has made three Arsenal starts and seven appearances from the bench this season.
This followed a highly-acclaimed display at the World Cup in Brazil, where he scored once and set up another as Costa Rica reached the last eight. Campbell also enjoyed a successful spell on loan with Greek side Olympiacos last season, where he made 43 appearances and scored 11 goals.
Everyone at Arsenal welcomes Gabriel to the club and wish Joel a successful loan spell in Spain.Copyright 2016 The Arsenal Football Club plc. Permission to use quotations from this article is granted subject to appropriate credit being given to www.arsenal.com as the source