Pablo Mari has arrived in London for a medical at Arsenal, with the club in talks with Flamengo to sign the defender on loan.
Arsenal are looking to sign the Spaniard on loan until the end of the season with an option to buy.
Mari signed a contract with Manchester City in 2016, but never played for them.
He went out on loan for three successive seasons to Girona, NAC and Deportivo La Coruna, before joining Flamengo on a permanent deal last summer.
The 26-year-old would become Mikel Arteta's first signing since taking over as Arsenal's head coach in December.
Mari's Flamengo sign won Brazil's Serie A, with the defender featuring in 22 of the 38 games, scoring twice as Flamengo finished 16 points clear of Santos and Palmeiras.
Arsenal will have to pay £30m if they are to buy Ukrainian defender Mykola Matviyenko from Shakhtar Donetsk.
The player's agent says the clubs are in talks about a deal for the 23-year-old, who has 18 months left on his contract.
Arsenal head coach Arteta has faced Matviyenko twice this season in the Champions League when he was assistant to Pep Guardiola at Manchester City.
Arsenal would prefer a loan deal over a permanent move.
How to follow the January transfer window with Sky Sports
Sky Sports will bring you the very latest news from the January transfer market with the return of three shows.
Start your day with Good Morning Transfers at 9am as our team of reporters bring you the latest news and insight. Transfer Talk then follows at midday delivering analysis of the biggest stories. Then join us at 7pm for the definitive round-up of the day's news with The Transfer Show.
Meanwhile, the Transfer Talk podcast will also be back at the turn of the year with more expert analysis from here and across the continent.
And as well as tuning into Sky Sports News, don't miss a thing with our dedicated Transfer Centre blog.