Arsenal are close to agreeing a deal worth up to £12m with Flamengo for defender Pablo Mari on an initial loan with an option to buy.
Sky Sports News reported a deal was hanging "in the balance" on Monday but a breakthrough in talks has increased confidence a deal can be done.
It is believed Arsenal amended the structure of the deal after a Flamengo director claimed they had changed the terms.
Arsenal have proposed a £4m initial loan fee to sign the 26-year-old until the end of the season with a further £8m option to make the transfer permanent in the summer.
The Spaniard was in London last weekend but returned to Brazil at the beginning of this week to resume pre-season training at Flamengo. He is expected back in the UK imminently to finalise his move.
If they do manage to conclude the deal, he would become Mikel Arteta's first signing since taking over as Arsenal head coach in December.
Flamengo have already thanked Mari for his contribution to their Copa Libertadores and Brazilian Serie A triumphs last season and said "the time has come to say goodbye" on social media.
Arteta says Arsenal's urgency to complete the signing of Mari has not been forced by the recent injury to defender Shkodran Mustafi - who escaped long-term ankle ligament damage.
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.
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