Arsenal have confirmed that David Luiz, Pablo Mari, Cedric Soares and Dani Ceballos have all signed contract extensions of varying lengths.
The quartet were all due to be out of contract on June 30, and Tuesday was the deadline to agree new deals to keep them until at least the end of the elongated 2019-20 season.
The Gunners have extended Dani Ceballos's loan from Real Madrid for the remainder of the campaign, while the other three players have committed their futures to the club beyond that.
David Luiz has signed a new one-year contract at the Emirates Stadium, while the loans of both Pablo Mari and Cedric Soares from Flamengo and Southampton respectively will become permanent deals when the transfer window reopens.
Both players have agreed "long-term" deals, thought to be four years, which will keep them at the club until 2024.
"I am really happy that we will have these players in our squad for the future. They have been part of the long-term technical plan Mikel and I have developed. They bring the right balance to our squad," technical director Edu told the club's official website.
"David is a really important player for us. He has played most of our matches this season and has been important for the team. His passing, his communication with the team on and off the pitch. He helps everyone.
"With Pablo we're all disappointed he got injured at Manchester City. Since Mikel arrived here he was asking for a central defender who was left-footed. We were really pleased with Pablo - his behaviour, the way he is training, his mentality and his quality. Unfortunately, he has that injury but of course we are really happy to keep him for the future.
"Cedric is also going to be an important player. He has been unlucky with the injuries but he is close to being ready and gives us more strength in the right-back position. We're also pleased Dani will finish the season here. He is making a good contribution and we look forward to him having a strong finish to the season."
Cedric is yet to make his debut for the club since joining from Southampton in January, while Mari is expected to miss the rest of this season through injury.